In a matter of just over three months, the Boston Celtics have gone from 11th place in the Eastern Conference to first. This team is firing on all cylinders right now, much in part to their top-ranked defense. However, they've been handed a devastating blow with the playoffs approaching.

Per Shams, big man Robert Williams, who is one of the best shot-blockers in the Association, is out indefinitely due to a torn meniscus:

This is awful news for the Celtics because Williams is truly a massive piece of their outstanding defense. He ranks second behind only Rudy Gobert with 2.2 swats per night while also averaging 10 points and 9.6 rebounds down low. The 24-year-old was injured in Sunday's blowout victory over the Minnesota Timberwolves. The Celtics are now 24-4 in their last 28 games.

It's unknown just how serious it is right now, but by the sounds of it, Williams won't be returning anytime soon. Boston was seen as a legitimate threat coming out of the East thanks to their star duo of Jayson Tatum and Jaylen Brown, but the loss of Williams definitely hurts their chances of making a legitimate run in the playoffs.

Al Horford has done a phenomenal job this season as well playing alongside Williams in the Celtics' frontcourt. That being said, it's almost certain Ime Udoka will shift Horford over to center in the absence of Williams.