Celtics head coach’s legacy on the line vs. Heat

The Boston Celtics dropped a winnable game against the Miami Heat on Wednesday. Erik Spoelstra's team was missing its star player in Jimmy Butler. Terry Rozier and Josh Richardson were also sidelined. However, Spoelstra gave his team the edge with smart coaching and a well-executed game plan. It's easy to forget that Miami consistently has the coaching advantage in the playoffs.

Suddenly, all eyes are on Joe Mazzulla. Boston's head coach led his team to the best record in the NBA. He has instilled a system that saw the Celtics rank first in offensive rating and second in defensive rating. And he entered this season on the back of taking his team to the Eastern Conference Finals in his rookie year, where they lost to the Heat. 

Mazzulla has a lot of doubters. He wasn't a unanimous pick for the Celtics' head-coaching gig. He took over in an interim capacity last season after Ime Udoka was suspended and ultimately released from the franchise. His good work with the team saw him earn the job full-time. Mazzulla was given a championship-level roster from the jump. 

How much of the Celtics' success is down to Mazzulla's coaching compared to their overall talent level? Facing a gifted coach like Spoelstra is a difficult task for most coaches in the NBA. Mazzulla hasn't fared well in this matchup. However, if he wants to be taken seriously, he must find a way to guide his team past the Heat in Boston's opening-round matchup.

The Celtics have no excuse for falling at the first hurdle. Especially not against a roster missing its best player and two of its most prominent rotation pieces. This is a series the Celtics must dominate. Wednesday's loss can be the only slip-up en route to the second round. 

Mazzulla is coaching for his job in this series. He will surely pay the price if the Celtics are bounced in the first round. More than that, though, Mazzulla is coaching to prove he belongs at the NBA level. He must prove that Boston's regular-season success wasn't just because of the talent at its disposal. 

Mazzulla is coaching for his legacy, and considering he's only in his second season, that is a strange concept to accept.