In a shocking turn in the sports world, one of the NFL greats in tight end Rob Gronkowski retired at the age of 29.

It's something that some pundits expected with the many injuries that have plagued him throughout his professional career. Gronkowski wasn't able to play a full season since 2011, while dealing with a multitude of injuries from forearm fractures to a torn ACL.

Despite these many setbacks during his time in the league, Gronkowski was able to revolutionize the tight end position in so many ways. He was a mismatch for any defender trying to cover him; too fast for linebackers, and too strong for defensive backs. He brought the Patriots offense to new heights and helped them achieve three Super Bowl victories during his tenure.

Gronkowski's retiring with the most receiving yards per game and the third-most receiving touchdowns by a tight end in NFL history. This is all while he missed 29 games because of injuries.

He had one of the most productive careers for a tight end, resulting in five Pro Bowls and four All-Pro selections. And unfortunately enough, he's had to have his time cut short because of nagging injuries — especially a career while he was still in his prime.

He joins a class of many incredible players that have had to stop their careers early because of a number of unique reasons. All of these players are incredibly talented and deserving of their acclaim and accomplishments. They've all earned their spots in NFL lore for their production, even if their careers got cut off short.

With that said, here are ten players that have retired early at 30 or younger.

10. Tony Boselli

The first-ever draft pick by the Jacksonville Jaguars was one of the pieces that catapulted the expansion team to early success. The left tackle was instrumental in taking the team to four straight playoff appearances after the team's first year in the league.

Boselli dominated for so long protecting Mark Brunell's blindside, helping the Jaguars offense become a top 10 unit in each season they made the playoffs, including two where they made the AFC Championship game. He was a towering figure that transformed the left tackle position for a young team trying to find their place. Especially during a time where players like Orlando Pace and Jonathan Ogden were taking over during the same time period. Both of them Hall of Famers, as Boselli should be.

Boselli was a five-time Pro Bowler and three-time All-Pro. He was a significant leader on a young Jaguars team trying to take the league by storm with his towering size at 6-foot-7 and 325 pounds. His flawless technique and dominance was demonstrated against the likes of Bruce Smith and Kevin Greene, to name a few.

However, with injuries that cut his time short, the USC product had to end his career at the age of 29. It's an unfortunate situation that will be very prominent on this list.

9. Earl Campbell

At a time when OJ Simpson's time in the NFL was winding down, Earl Campbell took over where the former left off. The former Heisman winner led the league in rushing in his first three seasons in the league and won AP Offensive Player of the Year award in each of those seasons as well as a 1979 MVP Award. And, he came away with a rushing triple crown in 1980.

During his first three years as the league's leading rusher, Campbell put together 5,081 rushing yards and 45 touchdowns. Only Eric Dickerson had a more productive first three years rushing in the league.

An incredible blend of both speed and power, he was the definition of a power running back. His highlights in the league are unimaginable, from head-butting defenders in the chest to running through people, even as they rip his jersey apart.

He was an instrumental piece during the Oilers run in the late-70s and early-80s. He assisted in guiding the Oilers to three straight playoff appearances and two consecutive AFC Championship games.

The five-time Pro Bowler had to cut his career short at the age of 30 when his bruising play caught up to him. His running style of reckless abandon is something that kept him from a long career.

His time after football continues to show his time in football has taken a toll on his body. He's developed arthritis in his hands and at times has to use a wheelchair for assistance in going long distances.

He was a phenomenal back during his prime and earned his place in the Hall of Fame in 1991 despite his short time in the league.

8. Kenny Easley

A safety that dominated during his brief time from 1981-1987, Easley was a perfect mixture of hard-hitting and awareness in coverage, and he was the prototypical safety for the Seahawks before Earl Thomas was even born.

Easley's strong play earned him five Pro Bowls and three All-Pro selections as well as the AP Defensive Player of the Year Award in 1984. That season, he came away with a franchise-record ten interceptions including two that were returned for touchdowns.

His time in the league came to a crushing end though, as his body was no longer able to continue his career after the Seahawks attempted to trade him to the Cardinals in 1987. In a physical, it showed that his kidneys were failing because of an overuse of opioids to treat his pains from playing football.

Even with him retiring at the young age of 28, Easley earned a spot in the Hall of Fame back in 2017. His impact in a shortened amount of time was something that earned him his place in NFL lore, as he came away with 32 interceptions and returning three for touchdowns. He also came away with eight sacks and 11 fumble recoveries.

7. Gale Sayers

As Sayers said, “Just give me 18 inches of daylight. That's all I need.”

And he proved that in his first season in the league, as he put up 22 total touchdowns in his rookie season. That record that wouldn't be topped until 1975 when OJ Simpson broke it.

Sayers was the definition of an all-purpose weapon. He could rush, receive, and return amongst the best of them. Sayers came away with 46 total touchdowns in his first three seasons in the league and was someone who exhibited incredible ability as a runner with his elusiveness and agility.

He led the league in rushing twice and came away with five All-Pro selections. However, Sayers' career came to a screeching halt as he suffered injuries in both of his knees. He retired in 1971 at the age of 28 and found himself earning his place in the Hall of Fame in 1977 at the age of 34. He still holds a remarkable 20 franchise records that still stand to this day.

6. Sterling Sharpe

A receiver with all of the talent in the world, Sharpe was only approaching just the surface of his success before his tragic neck injury. The older brother of Shannon Sharpe only made it to the age of 29 before calling it a career. But, before all of that, his accomplishments were something that would make some elite receivers of today jealous.

Sharpe was the first Packers receiver to lead the league in receptions since Don Hutson did it in 1945, doing so in just his second season. The former Gamecock also became the second receiver to complete the triple crown (leading the league in catches, receiving yards, and receiving touchdowns) during the Super Bowl era. The receiver that did that before him was Jerry Rice, and the only player to do that after Sharpe is Steve Smith in 2005.

The height of his success came when Brett Favre was brought to Green Bay in 1992. During his three seasons with Favre, he put together some of the best numbers in a three-season period. Sharpe put up 314 catches for 3,854 yards and 42 touchdowns. During that time, he came away with the aforementioned triple crown in 1992 as well as leading the league in receptions in 1993 with 112 (career-high) and receiving touchdowns in 1994 (career-high 18).

Unfortunately, he suffered his career-ending injury at the end of his 1994 season. He wasn't able to be a part of the 1996 Super Bowl-winning Packers team. He achieved so much in such a short time, as he came away with five Pro Bowls and three All-Pro selections.

5. Patrick Willis

One of the greatest inside linebackers of this generation and someone that was above the rest as well, Willis was a generational talent for the San Francisco 49ers coming onto a team with very little leadership or defensive presence.

Once he was brought to the 49ers franchise, the team atmosphere completely changed. His 49ers teams didn't experience much in regards to team success. However, Willis' play was something that would rival any inside linebacker of his time. A seven-time Pro Bowler and six-time All-Pro selection, the Ole Miss product proved to be someone that could change any struggling defense.

His dominance at the position cannot be understated.

He was a critical part for San Francisco's three consecutive AFC Championship appearances from 2011-2013. His statistics were something of Ray Lewis-caliber, as he came away with 20.5 sacks, 16 forced fumbles, five fumble recoveries, eight interceptions (two returned for touchdowns), and 60 tackles for a loss.

It was all in just eight seasons of play that he put together this strong resume of play. He chose to call it a career when he believed that his body could no longer play the game of football any longer.

He was a face for the 49ers franchise for so long, and it was a hard day to see him go.

4. Calvin Johnson

Continuing with modern players that retired early, here we have arguably the best receiver of the 2010 decade in Calvin Johnson. Looking at the teams he was on and the quarterbacks that were throwing to him only adds to just how incredible of a player he was.

Being drafted as the second overall pick, Johnson matched all of the expectations as being the best receiver in the league all throughout his time. A larger-than-life figure at 6-foot-5 with incredible athletic prowess to boot, he was a mismatch for any defense. Defensive schemes were created to attempt to take him out of the game.

Double-team or even triple-teams were not successful against Johnson, as he retired with 11,619 yards in just nine seasons to go along with 731 catches and 83 of them going for touchdowns. His receiving yards in nine seasons were the most by a receiver in their first nine seasons, trailing just Torry Holt and Jerry Rice. Since being drafted, no other receiver had more receiving yards, receiving touchdowns, or 100-yard games (46) than Johnson. His 5,137 receiving yards from 2011-2013 were the most in any three-season period.

Arguably his greatest feat is leading the league in receiving touchdowns in the Lions' 0-16 season with the likes of Dan Orlovsky and Jon Kitna quarterbacking that team. This goes along with his single-season record of 1,964 receiving yards in 2012, six Pro Bowls, and four All-Pro selections.

His time in the NFL ended at the age of 30 because of nagging injuries and feeling beat up after so much time, not to mention with no hope at a Super Bowl with the Lions.

3. Terrell Davis

Having just seven seasons to his credit, many would expect the usual amount of Pro Bowls and All-Pro selections for Davis, much like the others on this list. However, the accolades that come with Davis are something that surpasses many of the previous backs on this list.

  • All-time Broncos leading rusher with 7,607.
  • Davis is a two-time offensive player of the year in both 1996 and 1998.
  • He came away with three Pro Bowls and All-Pro selections to his name.
  • Two-time rushing leader including a 2,000-yard rushing season in 1998.
  • A 1998 MVP.
  • Two-time Super Bowl champion and Super Bowl MVP in 1997.

These accomplishments are something that made him the Hall of Famer that he is back in 2017.

He was a draft steal back in 1995 in the sixth round on a Broncos team in need of a rushing attack in John Elway's final years. Davis fit in perfectly right out of the gate as he improved each season he was in the league. He went from a strong 1,117 rushing yards in his rookie year to 1,538, then to 1,750, and then making the 2,000-yard rushing club with 2,008.

His impact in the playoffs was incredible, including rushing for eight touchdowns in the 1997 postseason that included the Super Bowl where he played through a migraine. He averaged 142.5 rushing yards per game in his eight career playoff games to go along with 12 rushing touchdowns.

His career came to an end when injuries halted his career to play at the age of 29. After suffering lingering knee injuries that stayed around during his final three seasons in the league, he retired in 2001.

2. Jim Brown

Still considered the greatest player of all time by some, Jim Brown chose to retire on his own terms. He played his final game at the age of 29 when he was still in his prime. It was an ultimatum made by Browns owner Art Modell while Brown was filming The Dirty Dozen that put him over the edge. It was to either be an actor or a football star, and Brown chose the former.

He retired as the most accomplished football player in history, and he was a mile ahead of all players in terms of what he accomplished as well.

Brown retired with:

  • A 1963 Bert Bell Award.
  • Pro Bowl and All-Pro honors in every year he played (nine each).
  • Four rushing triple crowns (1958, 1959, 1963, and 1965).
  • His single-season rushing yards record for the Browns is still not broken and is the longest standing single-season record out of any franchise.
  • He retired with the most rushing statistics in every major category (except yards per attempt which he placed second), including being one of the top in rushing yards all-time (11th; 12,312), rushing touchdowns all-time (fifth; 106), and total touchdowns all-time (10th; 126). He's also still the all-time leader in rushing yards per game (104.3).
  • Three-time league MVP and won his NFL Championship in his final season.

He accomplished everything he possibly could in the NFL, and he chose to retire early not because of injuries. Brown retired because he chose to pursue something different and because of Modell.

It's unfortunate considering he was still the best player in the league by the time of his retirement. He came away with a triple crown in his final year with 289 rushes for 1,544 rushing yards and 17 rushing touchdowns. He added 34 catches for 328 yards and four touchdowns as well.

His time in the league only kept him until he retired in July before the 1966 season. Because of this, he joins this list of phenomenal players that retired at the age of 30 or younger.

1. Barry Sanders

Would any list regarding NFL legends retiring at 30 or younger be complete without the mention of Barry Sanders?

He's the third-leading rusher in league history (15,269), tenth in rushing touchdown (99), and seventh in yards from scrimmage (18,190). He's also come away with four rushing titles, two Bert Bell and Offensive Player of the Year Awards, a 1997 NFL MVP, and ten Pro Bowls and All-Pro selections each.

He produced some of the best statistics for a running back every season he was a part of the Lions organization. He put up at least 1,000 rushing yards every season he was in the league, and to add to how outstanding he was as a back, when taking away his negative yard plays (which is believed to be 1,114) his career rushing average would be 6.3.

His highlights are something out of a video game, as he was somebody that could evade almost any tackler in his way. Sanders was a running back that unfortunately played for a Lions teams that never went far whenever given a shot at the playoffs. The Lions were 76-84 during the Sanders era and only came away with one playoff win in five appearances.

His decision wasn't made because of injuries. It was more because of a realization of everything “coming full circle.” As he stated in his book:

It was tough to stay focused and motivated.

The realization that management no longer cared about winning slammed me harder than any linebacker had ever hit me in my entire career. That realization trivialized everything I did during the off-season to prepare myself. It trivialized everything I dreamed about from the time I was a kid in Wichita.

He did say that he was happy with the decision that he made though.

I had already achieved a level of success that gave me much satisfaction and pride. I didn't need to pass Walter [Payton] to prove that to myself.

He was a generational talent that was used on a team that went nowhere. It's unfortunate, but he still gave all of us football fans something to enjoy during his time before retiring at 30, much like all of these others on the list.