BOSTON — Al Horford returns to TD Garden on Thursday night and, with him, comes yet another reminder of what the Celtics now supposedly lack.

While the Celtics eased the departure of Kyrie Irving by signing Kemba Walker, Horford’s exit — combined with the team trading away Aron Baynes to clear the necessary space to sign Walker — left Boston without two of its defensive anchors. One of the primary storylines around the team since Horford’s exit has been prognosticators loudly wondering how Boston could possibly patch the defensive void left behind.

Already past the quarter pole of the 2019-20 season, these new-look Celtics rank fifth in the NBA with a defensive rating of 103.3. They sit a fraction of a point behind third-ranked Philadelphia (and their Horford-infused defense) and Boston’s ragtag group has more than held its own.

Still, despite all of Boston’s early season success, many talking heads continue to insist that the Celtics need an upgrade at the big-man position to truly contend in the East.

This sort of declaration is met with shoulder shrugs from the players who currently hold down the fort in Boston’s frontcourt. This past summer, the Celtics re-signed Daniel Theis and picked up both veteran Enes Kanter and French rookie Vincent Poirier. Boston used a 2019 first-round pick to nab Grant Williams with hopes that he could play as an undersized big and Boston is banking on a second-year leap from 2018 first-round pick Robert Williams.

Every one of Boston’s bigs brings something different to the table. Conversely, they all have a notable deficiency. Kanter has heard all about his defense; Theis can get overpowered by beefy bigs; Robert Williams knows he needs to play with more consistency; and Grant Williams is shorter than some of Boston’s primary perimeter players.


But Boston’s bigs just smile when asked if the perpetual scuttlebutt about the Celtics needing a frontcourt upgrade bothers them.

"I don’t listen to it,” said Theis, a German import now in his third season with the Celtics. Boston’s defensive rating is a rock solid 98.9 when Theis is on the court and, among players averaging at least 15 minutes per game with 10 appearances, Theis ranks 16th overall in the NBA in defensive rating.

"We have so many bigs and it’s whoever plays good that night,” said Theis. "You don’t guard the best bigs with one person. It’s a team effort. We’re [the third best team] in the East and we’re playing really good basketball as a team. So, no, I don’t listen to that.”


Kanter said he bravely dives into his social media mentions after games and sees all the burns about his defense. He is unfazed and has embraced trying to positively impact both sides of the court.

“I don’t ever take [the criticism] personally,” said Kanter. “We’re just going to go out there, our big-man unit, and show that we can do it.

“Now, it’s my ninth-year in the league, man. I used to take [the criticism] really really serious and let it get to my head. Now, I look at the comments and I’m like, ‘Yeah, right, OK.’” 

The Celtics own a defensive rating of 100.8 when Kanter is on the court. The number actually spikes 1.1 points when he’s on the bench. The NBA’s tracking data has Kanter holding opponents to 52 percent shooting, or 4.9 percent higher than those players' typical averages, but much of that has been Kanter getting burned by 3-point shooters on the perimeter.

Kanter is never going to be an elite defender, but he praises coach Brad Stevens and the coaching staff for putting him in position to be successful. Kanter takes great pride, too, in the way he held up while starting opposite Embiid on opening night. Embiid scored 8 points on 3-of-7 shooting during 6 minutes of matchup time. 

Thursday night will hopefully give us a better look at whether Kanter can truly engage in hand-to-hand combat with Embiid.

It’s another big week for Theis, too. He’s clung to the team's starting center spot since the second game of the year. The scouting report screams that he can’t hang with strong bigs like Embiid but, good night or bad, Theis can’t wait to try.

Nikola Jokic gouged Theis for 16 points on 8-of-16 shooting in two matchups this season, according to the NBA’s defensive tracking data. Tristan Thompson got Theis for 10 points on 4-of-7 shooting, while Antetokounmpo had nine points on 4-of-5 shooting. Stevens has turned to Kanter, when healthy, to add some heft, or Robert Williams with hopes of countering size with athleticism. But Theis, now further removed from the meniscus tear that ended his 2017-18 season, looks springier than ever and his 3-point shot is ramping up again.


Maybe more importantly, Theis hasn’t pouted when Stevens gives him an early hook and he’s embraced the notion that defending elite bigs isn’t a one-man job.

“It’s a challenge but it’s also a team effort because those guys, especially someone like Embiid, it’s hard to guard them 1-on-1 for 35 or 38 minutes,” said Theis. "He gets his shots, he’s fierce, he’s big. It’s hard to guard him 1-on-1 during the game, so it’s a team effort.“

“That first game, Kanter did well. He tried to wear him out, try to get him tired. I take it as a challenge against him. With Jokic, and [Indiana’s Domantas] Sabonis, and Joel — it’s fun.”

The Celtics will keep their antennas up as trade season arrives on December 15 but, because of their lack of tradable salaries (as detailed in this week’s Celtics Mailbag), it feels like it’s going to be hard to make a move that isn’t an overpay for what might ultimately be a marginal upgrade. Maybe the buyout market could present an intriguing body, but there’s a lot of basketball before that point.

Grant Williams has earned Stevens’ trust with his smarts and an ability to make the right play more often than not. But he’s still a rookie and one who hasn’t made a lot of shots. Robert Williams oozes athleticism and raw potential but for every loud lob he throws down or volleyball block he uncorks, there’s a defensive lapse or a head-slapping turnover.

Robert Williams has one notable supporter in his corner: Horford. The two shared a moment after the season-opener in Philadelphia with Horford offering a vote of confidence about Williams’ potential in this league. Robert Williams said he’s eager to model parts of his game after Horford, who he tried to absorb from before the roster maneuvering began this past summer.

Stevens doesn’t have the luxury of a Horford or Baynes to clog up the back line any more. But his team isn’t struggling because of it. Games like Thursday might help determine if it’s sustainable.

Yes, it's another chance for Boston’s new group of bigs to show that this team doesn’t need an upgrade as badly as some seem to think they do.

Don't miss NBC Sports Boston's coverage of Celtics-76ers, which tips off Thursday at 7 p.m. with Celtics Pregame Live, and then Mike & Tommy have the call at 8 p.m. You can also stream the game on the MyTeams App.