The Celtics knew what they had in Daniel Theis.
Lukewarm as that compliment may be towards the veteran big man — and as unevenly as his return to Boston progressed through his NBA Finals benching — Theis built up so much rapport with the core members of the Celtics over nearly five seasons that his presence lent some comfort behind Al Horford and Robert Williams III. It wouldn’t be stunning if he ends up back with the team one more time before his career ends.
However, Theis’ $8.7 million salary became a necessary component of the Malcolm Brogdon trade, leaving the Celtics without a backup center who’s logged significant NBA service time in green. It’s a potentially glaring hole on a roster now packed with stalwarts and one that’d be disappointing to see cost a team with legitimate championship aspirations.
Several options exist to fill it, but Boston has moved slowly in filling its final three roster spots as they search for that reliability and comfort, some of which they already see on the roster. The expiration of the $17.1-million trade exception already closed one avenue to address it.
Horford and Williams III staggered minutes at the 5 last season and spelled each other’s minutes. A desire to scale back Horford’s workload and everlasting Williams III injury concerns made the presence of Theis all the more important. The burden Horford shouldered when Williams III tore his meniscus and long postseason run that followed created an even bigger onus on resting Horford this season. As it stands, it could be difficult to minimize him if Williams III gets hurt. With Danilo Gallinari and Grant Williams focusing on providing Horford insurance at the 4, only Luke Kornet projects to make spot appearances exclusively at center.
Brad Stevens and Ime Udoka both affirmed the Celtics’ intention to bring another big man into the fold during Summer League. It’s unclear if Mfiondu Kabengele counts after he signed to a two-way contract last week.
Stevens and Udoka praised Kornet’s abilities, while previewing smaller lineups and the potential for a bigger wing in Gallinari to spend some time inside, too. Grant played center as a rookie and consistently guards bigs, so there’s potential for the Celtics to creatively fill Theis’ loss. It seems increasingly likely that’s the route they’ll take over free agency, but there are still options on the market.
“We’ll continue to look at what adds to our team,” Stevens told CelticsBlog earlier this month. “I think ultimately, though we started big most of last year with Al and Rob, we oftentimes would play one of them. I think, like I said earlier, we’re better set up to play "smaller" than we were just because of the size of (Brogdon and Gallinari) sitting next to us. Got a lot of different options there. We’re really high on Luke, we’ve been really high on Luke, we thought he had a terrific G-League season and think that he can step right in and be a passer and a ball-handler and a mover and a screener and a roller when need be ... we’re really believing in Luke, not only as depth, to obviously fill out the roster, but also be ready to help us and help us win. I think he’s at that stage where he can do that. We’re still looking, and we’ll still add at least one more body at whatever we call the five position nowadays.”
Dwight Howard, Demarcus Cousins, Montrezl Harrell, LaMarcus Aldridge and Tristan Thompson headline the remaining centers available to sign. It’s an uninspiring, largely declining aging group who didn’t help their teams significantly one year ago.
Their availability also underscores the declining demand for depth centers. Some teams have moved toward small ball later in games and utilized an increasingly versatile talent pool in the league to play multiple positions. Think about the Cavaliers — who start three players with center size and still found a cheap backup in Robin Lopez, or the Warriors’ usage of Draymond Green and Kevon Looney.
Timing made Boston especially thin though, since they traded Theis after the wave of free agency signings like Lopez or Andre Drummond. The traditional backup 5 like Theis, who himself could play the four more capably than the players listed above, brought a narrow set of skills that become less tangible as the playoffs progress. Drummond got taken out of Round 1 last postseason.
What the Celtics need, barring an emergency, is an innings eater. Someone who, alongside an increasingly interchangeable rotation, can maintain Boston’s defensive stature and provide 10-15 solid minutes through the middle portions of regular season games.
That’ll require more minutes and stability from Williams III and generally consistent availability from Horford. That’s a gamble, but one minimized by Boston’s ability to play two or even three guards alongside Jaylen Brown and Jayson Tatum, as long as one center is available. If Williams III can log over 35 minutes, part of Udoka’s emphasis on internal growth, alongside the guards and forwards while Horford sits, that leaves a small difference inside.
Kornet won’t inspire significant confidence compared to Williams III, Horford, or even the average starting big man. He only needs to be compared to Theis though, who wasn’t at his best, averaging 7.9 points, 4.7 rebounds and 0.7 blocks per game on 59.8% shooting (10/28 3PT) last season in Boston. Kornet posted 4.4 PPG, 2.9 RPG and 1.4 BPG on 47.3% shooting in his 2021 Celtics stint, while averaging 14 minutes in his spot appearances. He made strides in ten Maine appearances this year, shooting 50.6% from the field, 31.4% from three with 11.9 PPG, 7.6 PPG, 3.9 APG and 2.6 BPG. That production should translate to respectable backup production if Boston’s down one center short term.
“We’ve talked about adding another big,” Udoka said at Summer League. “With nights where Al being a little older might take a rest night or Rob, having another possible starter. We’ve obviously got Luke Kornet, who’s grown throughout the season as well, some of the young guys you’ve seen.”
Kornet and even Kabengele could step into the backup role occasionally, and not play at all come the postseason. Theis regularly received DNP-CDs. Given the Celtics’ unconventional starting lineup, which Udoka hinted will likely remain the same, Kornet’s role could become dispensable, especially where Boston has built one of the more interchangeable rosters in the league. It’s part of, as Stevens noted, the evolution of the league beyond positions.
Size matters if the label center doesn’t though. While Grant can switch onto centers and Gallinari may be able to play some drop defense inside at 6'10", neither provide extensive experience being the biggest man on the floor, guarding the interior, rebounding at a high rate or keeping opposing bigs off the glass. The attributes you still look for from centers.
Basketball Reference credited Gallinari with playing 36% of his 2021 minutes at center, then 24% in 2022 after effectively never playing center prior. Grant played 6% of his time inside as a rookie, 7% in 2021, then 3% this year, moving to nearly exclusive 4 minutes under Udoka. Gallinari’s interior role coincided with Atlanta’s porous defenses, and he only averaged 4.4 RPG and 0.2 BPG these past two years, while allowing 48.8% shooting to opponents in 2022. Williams slimmed down to play a more perimeter role in 2021-22 and proved better as a roamer than interior bruiser.
“My position is going to backup 4, but whatever needs to be done, I’ll do it,” Gallinari said on CLNS Media’s A-List Podcast. “I can play different positions, I’ve never played 5, but if it’s something that needs to be played, I’ll play. No problem. Whatever needs to be done.”
Versatile rim protection also keyed the system that made Boston the league’s top defense. Horford thrived in a drop scheme while Williams III’s roving away from weaker perimeter threats away from big man assignments proved borderline revolutionary. Udoka’s instincts will lean toward playing with size, and while Kornet mimics some of those attributes defensively, he’ll need to hit shots in the pick-and-pop and crash the glass to impact offense.
If there’s an emergency where the Celtics lose multiple big men, they may need to take a flier on a free agent or utilize either their $5.9-million or $6.9-million trade exceptions — which expire around the trade deadline. Khem Birch, Jaxson Hayes, P.J. Washington, JaVale McGee, Goga Bitadze and Boban Marjanovic headline some names that fit the smaller TPE's and could feasibly become available later if circumstances break right.
That’s likely the Celtics’ bet — don’t force a roster addition that isn’t needed now, trust the roster’s depth and versatility to figure out those minutes and buy later at lower cost. They can add up to six more players through the end of training camp. Kornet’s new contract is guaranteed for $300,000 on Aug. 15, with larger guarantees kicking in on Opening Night.