The Green Bay Packers 6-9-1 record last season was extremely disappointing and left a lot to be desired. That doesn't mean there were some standout performers on both sides of the ball though. For Green Bay, one of their best players in 2018 was linebacker Blake Martinez.

With 2018 now in the rearview mirror, it's time to look at 2019 and what can be done. The Packers have the talent to be an elite team in the NFL, especially with quarterback Aaron Rodgers at the helm. However, he can't do it alone. Rodgers will need other players to step up and contribute as well.

On the defensive side of the ball, Blake Martinez has the opportunity to be their Rodgers. With that in mind, he could be the biggest X-Factor for the Green Bay Packers in 2019.

The Packers have Aaron Rodgers to command their offense. He makes everyone around him better and will give them an at-worst solid offensive unit. However, there isn't much he can do to help the defense except winning the time-of-possession and field-position battles. Outside of that, the defense will need to rely on someone else to do the heavy lifting.

That's where Blake Martinez comes into play.

The linebacker finished 2017 with 144 tackles and one sack. He managed to improve those numbers last season, finishing with 144 tackles again – but this time five sacks. Martinez is the clearcut leader of the defense, and it makes sense seeing as he's at the typical field general position of middle linebacker.

Not only is Martinez a leader, but he just might be their most important player.

Martinez is the key to every facet of the defense. He's a major help in the run game, filling up holes and being one of the more sure-tacklers in the NFL. Keeping the running back from getting to the second-level can make a major difference in the outcome of a game.

In the passing game, Martinez is a solid coverage man who is athletic enough to not be too much of a mismatch too often. Meanwhile, he's extremely good at getting to the quarterback, especially for his position. Keeping the QB uncomfortable is obviously something a defense wants to strive for and he's a big help in that part.

The Green Bay Packers are in a division (NFC North) with a lot of offensive talent.

The Chicago Bears have Allen Robinson at receiver with up-and-coming QB Mitchell Trubisky throwing him the ball. One of the best ways to slow them down is to get Trubisky off his game. He's not the most accurate passer in the league, so not allowing him a clean pocket could really destroy the rhythm of the offense. Meanwhile, plugging holes for running back Tarik Cohen is a must.

For the Minnesota Vikings, it's more of the same. Kirk Cousins is more accurate than Trubisky but has been known to struggle once he's pressured. Making things difficult for Cousins makes things difficult for the entire offense. If you can shut down him, Adam Thielen and Stefan Diggs become neutralized as weapons from the wide receiver position. Dalvin Cook is a running back you don't want to allow to pick up steam. Keeping him behind the line of scrimmage before he can reach that second gear is the name of the game.

Finally, the Detroit Lions are all about the passing game. That means putting pressure on QB Matthew Stafford and matching up with their wide receivers and tight ends. If you stop the pass you've likely stopped the offense.

Those are all things that Blake Martinez can lead the Green Bay Packers defense on. He can stop the run with the best of them. Meanwhile, he's a good defensive matchup for tight ends and can even contain some receivers. Finally, his ability to hold zones and rush the quarterback will make things miserable for opposing offenses. He's the key to the defense's success, making him one of the biggest X-Factors on the Green Bay Packers in 2019.