Marcus Smart is kind of like the Andre Iguodala of this young Celtics team. He's a little overlooked because he doesn't seem to produce a whole lot when you look at the box score, but it's all about the intangibles and the deep, deep stats.

Here's why the Celtics can't, under any circumstances, let Smart walk away:

That is a huge difference. 

In the East, that's a team going from a likely top two or three seed to the sixth or seventh seed. Without Smart, the Celtics are a good team but with Smart, they're a top-tier contender and a real problem.

His teammates know it too.

Just look at the difference. Greg Monroe is literally nothing without Smart and surprisingly enough, Kyrie Irving performs a lot better when playing alongside him. Maybe it has something to do with Smart's tenacity on the defensive end.

Marcus Smart is the glue guy for the Celtics. 

He does all the little things that have a big impact when put together. If he gets his shot going? Then damn, that's just a bonus because with Jayson Tatum, Kyrie, and Gordon Hayward already on the team, you'll really be in trouble.