The Celtics have been steamrolling opponents over the last two months, going 20-4 since the calendar flipped to February. They completely morphed their form from the team that was .500 through the first 50 games of the season, catapulting themselves from the Play-In picture all the way to a fight for first place in the Eastern Conference in the final two weeks of the season.
Looking like legitimate title contenders, the Celtics own the top offensive and defensive rating in the NBA since the start of February, giving them a 14.5 net rating in that span, the best in the league by a mile. In fact, that net rating is almost a full 10 points per 100 possessions better than the next closest team in the East, the defending champion Bucks (5.2). If you need further proof of how truly dominant Boston has been, it owns a +334 point differential over that 24-game stretch, also by far the best in the NBA.
Just when it looked like there was nothing that could stop this team's momentum from rolling right into the NBA Playoffs, they were hit with some adversity during Sunday's victory over the Timberwolves.
Rising star center Robert Williams III went down with a knee injury during the game and did not return. While the entire city collectively held its breath overnight awaiting MRI results, ESPN's Adrian Wojnarowski reported on Monday that Williams suffered a meniscus tear in his left knee and will "minimally miss several weeks."
Later on that afternoon, head coach Ime Udoka made it clear that Williams' torn meniscus will require surgery, but the type of surgery he needs will determine whether or not he will be able to return at any point in the playoffs.
The latest: Williams could return within four-to-six weeks, per Wojnarowski.
Williams just signed a (very team-friendly) four-year, $54 million contract extension that doesn't kick in until next year. While his absence hurts the Celtics' championship hopes this season, it wouldn't be worth risking a long-term issue for a young big man who already has an injury history.
If Williams isn't available for the remainder of the season, where does Boston go from here and how would it impact the Eastern Conference playoffs and beyond?
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How have the Celtics played without Robert Williams?
It's fair to assume the Celtics will be cautious with their 24-year-old center who has emerged as one of the best rim protectors in the NBA during a breakout season in which he is being considered a Defensive Player of the Year candidate.
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Williams has missed 15 games already this season and Boston was a pedestrian 7-8 in those contests. The Celtics' defense has been so suffocating that Williams' on/off numbers don't really do his impact justice on that end of the floor.
| OFF RTG | DEF RTG | NET RTG | |
| On court | 113.4 | 103.4 | 10.0 |
| Off court | 110.1 | 106.0 | 4.0 |
With Williams on the floor, the Celtics' offensive rating ranks top 10 in the league, while their defensive and net rating are the best in the league. Boston's net rating when Williams is on the court is the second-highest on the team (for players who have been on the Celtics all season), only trailing Jayson Tatum.
With Williams off the floor, the Celtics have still been one of the NBA's top defenses, but their offense falls into the bottom-10 in the NBA.
Is it possible Boston will miss Williams more on the offensive end than the defensive end? No. But the on/off numbers do show how vital Williams is as a safety valve for slashers like Tatum and Jaylen Brown, giving them an easy out as a lob threat when defenses crash too hard on their drives.
The Celtics have a lot of ground to cover on both ends if Williams is out for the season, so who will step up?
Who steps up in Robert Williams' absence?
Williams has been the anchor of Boston's defense, but not in a way that you typically see from traditional rim protectors like Rudy Gobert or Joel Embiid. Udoka has used Williams as more of a free safety this season, sticking the 6-foot-9 athlete on opposing teams' lesser offensive players, allowing him to roam freely to help off of his assignment and swat shots away at the basket.
As a result, Williams' 2.2 blocks per game and 134 blocks are both second in the league to Grizzlies forward Jaren Jackson Jr. He's holding opponents to 52.1 percent shooting at the rim, which is good for top 10 in the league and on par with other Defensive Player of the Year candidates like Gobert (52.0 percent) and Giannis Antetokounmpo (53.1 percent).
This one's a little more niche, but as ESPN's Kirk Goldsberry pointed out, Williams' 0.90 points per shot as the closest defender is the lowest rate in the NBA, ahead of even Gobert (0.93).
So how do you replace a unique defensive stopper like that? You don't, but Al Horford, Daniel Theis and Grant Williams will have to try.
Horford has been revitalized this season, turning back the clocks to the version of himself that left Boston back in 2019. He still brings that same savvy defensive IQ to the floor, using his instincts to make up for whatever he lacks in athleticism. Grant Williams has emerged as one of Boston's most versatile defensive pieces, taking on assignments from bigs like Domantas Sabonis and Julius Randle to slashers like Pascal Siakam and even guards like Shai Gilgeous-Alexander.
Those two will allow Boston to continue to run its switch-heavy defensive scheme that has turned it into a championship threat, but Theis will take on the biggest promotion in his role, going from a bench player to a key reserve in the rotation.
When the Celtics traded Dennis Schroder to the Rockets at the trade deadline to bring Theis back to Boston, it got lost in the mix of everything else that happened that day. Now, knowing Williams may miss the remainder of the season, that trade becomes one of the most important of the deadline, giving the Celtics another familiar frontcourt piece to slide up on the depth chart.
Theis has the mobility to play a similar free safety role as Williams, he just isn't as switchy on the perimeter and can't protect the rim at as high of a level, of course.
With Horford all but certainly filling Williams' spot in the starting lineup, Theis now becomes the first (and only) big man off the bench, and the Celtics will need him to provide meaningful minutes even when the rotation shortens up in the playoffs.
How does Robert Williams' absence affect playoff matchups?
With how close the Eastern Conference standings are right now – only one game separates first place and fourth place – it's nearly impossible to predict playoff matchups, even with fewer than 10 games to play.
MORE: NBA Standings: Seeding scenarios, breakdown ahead of 2022 NBA Playoffs
With that being said, the Celtics will surely have to go through some combination of Embiid, Antetokounmpo or Bam Adebayo to get out of the East. If they make it out of the East, waiting for them could be one of Deandre Ayton, Jackson and Steven Adams, Draymond Green, Gobert or Nikola Jokic.
While traditional thinking would have you assume Boston doesn't have a matchup for those players without Williams, he actually wasn't drawing those matchups directly at all this season (as mentioned in the section above). Horford was the primary defender for all three of those players in the East – Embiid, Antetokounmpo and Adebayo — and mostly all of the dominant frontcourt opponents the Celtics have faced.
Williams' threat as a lurking help defender will surely make life tougher on Horford, but that's where Udoka will have to get creative with traps and double teams to give the 35-year-old some support.
Williams' injury doesn't completely tank the Celtics' hopes of a run to the NBA Finals, but it requires Boston's already thin frontcourt to take on much more responsibility on defense and makes life a little more difficult for its primary scorers on offense.
