Head coach Joe Mazzulla isn’t messing around when it comes to rebounding.
It’s no surprise that the Boston Celtics have looked shaky on the glass to open the preseason. Between Jayson Tatum’s injury and the offseason departures of several bigs, Boston is missing four of its top five rebounders from last season.
To emphasize the importance of cleaning the boards, Mazzulla has taken an unusually strict approach. During the opening quarter of Boston’s first preseason game against the Memphis Grizzlies—when the Celtics surrendered five offensive rebounds—Mazzulla began benching any player who gave up a second-chance opportunity.
It’s an extreme tactic, and one that probably won’t carry into the regular season, but it reinforces a clear message: under Mazzulla, consistent minutes will have to be earned through attention to fundamentals.
Joe Mazzulla Has Correct Approach to Celtics' Rebounding Woes
Through three preseason games, the Celtics are corralling just 64.3% of defensive rebounding opportunities, according to NBA.com. For comparison, the Philadelphia 76ers finished last in the NBA last season at 67.8%—still 3.5 percentage points higher than Boston’s current mark. The Celtics haven’t posted a sub-70% rate over a full season since 2012-13.
It’s a small sample size, but Mazzulla clearly finds the results unacceptable.
On Sunday against the Cleveland Cavaliers, Boston gave up three consecutive offensive rebounds on a single possession during the second quarter. Mazzulla responded by calling for a substitution after each one, sending Derrick White, Josh Minott, and Sam Hauser in for Anfernee Simons, Neemias Queta, and Hugo González.
Even Jaylen Brown wasn’t spared. After failing to box out Dean Wade late in the first quarter, Brown was pulled from the game. His shift was nearing its end after about nine minutes anyway, but the lapse sealed it.
Mazzulla is installing a no-nonsense philosophy regarding his team’s rebounding efforts. Even if the strict in-game punishments fade when the season begins, his stance is unmistakable: rebounding effort will define playing time.
Balancing Pace and Control
While the rebounding numbers are troubling, there’s some context behind them.
The Celtics are a team looking to redefine itself after a whirlwind of offseason transactions. Under Mazzulla, Boston has built an offensive identity around pace, spacing, and three-point volume.
With Tatum sidelined and several key contributors gone, Boston is expected to rely more on tempo to generate offense. Players and coaches alike have emphasized a renewed focus on pushing the pace to create easier looks, wear down opponents, and get more production from their bench.
So far, it’s working—Boston’s preseason pace of 105 is significantly higher than last year’s mark. But playing faster can also lead to defensive breakdowns and missed rebounding assignments, especially in transition. Getting out and running can help a team with less offensive firepower, but not if it comes at the expense of defensive control.
To their credit, the Celtics have been strong on the offensive glass, averaging 15.7 offensive rebounds per game, the third-best in the league behind only the Portland Trail Blazers and Orlando Magic. The challenge is transferring that same aggression to the defensive end.
Who Can Step Up?
Overcoming their frontcourt inexperience will take a collective effort.
Newcomers Luka Garza (7.0 RPG), Josh Minott (6.3 RPG), and Chris Boucher (5.0 RPG) have been Boston’s top rebounders so far this preseason. Each of them is a veteran in the league, but has yet to see consistent playing time. That can change this season on a retooling Celtics roster, and they each look eager to prove they belong. With Mazzulla enforcing a short leash, that hunger is translating into results.
Still, their impact hasn’t been enough to elevate the Celtics’ overall performance on the boards—at least not yet. If Boston wants to stay competitive without Tatum and other key veterans, improving on the glass isn’t optional—it’s essential.
And for Mazzulla, that work starts now.