Prior to the beginning of the 2019-20 campaign, not a lot of pundits envisioned the Miami Heat to be the first squad to advance to the Eastern Conference Finals.

Yet, the Erik Spoelstra-mentored club defied all expectations and have only lost once in nine playoff games so far.

By now, Miami already proved why they are the dark horse team in this year’s playoffs with their masterful dismantling of title-favorites Milwaukee Bucks in just five games.

The Heat now has worthy opponents in their quest to hoist the Larry O’ Brien trophy once more, as the Boston Celtics dethroned the 2019 champions Toronto Raptors in their grueling semis series that stretched seven games.

While Miami’s All-Star tandem of Jimmy Butler and Bam Adebayo will still be the catalysts of their attack, the Heat’s x-factor in this series will be their 20-year-old, sweet-shooting first-year player.

Tyler Herro began the year as the second-best rookie in the Heat roster, taking a backseat to the undrafted Kendrick Nunn.

But once he found his groove in the pros, it became clear that the 6-foot-5 Kentucky alum does have the potential to be one of the brightest stars in the league one day.

Some argue that Herro has already shown shades of Phoenix Suns superstar Devin Booker. Getting some valuable playoff experience in just his first year will also likely speed up his development process.

Here are three reasons why Herro will be key in Miami’s East Finals series versus Boston:

Herro will be Miami’s “fourth man”

As mentioned earlier, the Heat’s systematic approach on offense and defense starts and ends with Butler and Adebayo. Miami’s veteran point guard Goran Dragic has also come alive in the postseason and looked a lot like his All-Star form in the first two rounds.

Celtics head coach Brad Stevens’s defensive scheme will certainly key in on this Heat trio. As good as the team is defensively it will be hard for them to win four times this series if they won’t be able to contain Miami’s fourth option.

Enter Herro, who has already earned coach Spo’s trust and has been given valuable minutes in his first postseason.

While his best strength will always be his efficiency from downtown, Herro has shown he can attack the lane and make plays for others when needed.

While the C’s have a defensive juggernaut in Marcus Smart, he’ll likely have his hands full with either Butler or Dragic. Herro simply needs to pick his spots and be in the right place at the right time. Coach Spoelstra will certainly put him in those positions against the Celtics.

Herro has gotten better in the playoffs

The former Wildcat earned his stripes in the regular season where he notched impressive tallies of 13.5 points, 4.1 rebounds, and 2.2 assists, while shooting 42.8 percent from the field and 38.9 percent from deep.

While most of his peers would struggle in their first playoff foray, Herro has been the polar opposite. Herro has upped his scoring output to 16.3 points on a blistering 40 percent shooting clip from deep in nine playoff games.

The former SEC Newcomer of The Year has nailed at least one 3-pointer each playoff game and has proven that he has no issues “playing hero” when his team calls his number come crunch time.

Boston will have to pick their poison with Herro, Robinson

Celtics coach Brad Stevens has called Herro “one heck of a player”, so its clear that he is already wary of his capabilities.

If the C’s do clamp down on Herro and chase him away the 3-point line, the Heat have another flamethrower in the form of Duncan Robinson.

Robinson was tied third with Damian Lillard for most 3-point makes in the regular season (270) with an ultra-efficient 44.6 percent success rate.

While Robinson starts games for the Heat, Herro is usually the first man off the bench. This gives him a chance to get hot early against Boston’s second unit.

Coach Spo likes to have both snipers on the floor in tight games, and the Celtics’ defenders will have their hands full chasing these two around.