“Al is coming back for next year,” Grousbeck said. “That’s what I’ve been told. Ironically, we won in [2008] over Al’s team. The [Atlanta] Hawks took us to seven in the first round. So we were part of his drought, and now he came home to us. He loves it here — he and his family love it here. He couldn’t be happier, and we are also happy to have him.”

Horford, a five-time All-Star who last earned a selection during his first stint with the Celtics in 2017-18, has one year remaining on a two-year, $19.5 million deal.

Al Horford Helped Celtics Win NBA Title Despite Injuries to Kristaps Porzingis

Horford was an invaluable member of Boston’s rotation during the playoffs, particularly after an injury to Kristaps Porzingis sidelined the team’s starting center from the middle of the first round until Game 1 of the Finals.

Horford averaged 9.2 points, 7 rebounds and 2.1 assists across 19 postseason games, per StatMuse. He also connected on nearly 37% of his 3-point attempts, which allowed for the adequate floor spacing the Celtics need to take advantage of mismatches in their five-out scheme.

Defenses don’t have to respect Horford in the same way they must respect Porzingis as an explosive offensive threat. However, Horford was good enough in his stead.

Horford, now 38 years old, also can’t offer the Celtics the type of rim protection Porzingis does. However, he remains versatile enough on defense to switch regularly and keep quality offensive players in front of him, which he did effectively against the Dallas Mavericks in the Finals.

Tim Bontemps of ESPN has pointed out throughout the postseason that Horford is considerably more impactful overall when he plays between 25-30 minutes. However, even when he had to play into the mid-30s or up to 40 minutes (the latter of which he did twice during the Eastern Conference Finals against the Indiana Pacers), Horford proved he had enough in the tank to carry the load from the center spot.

Jayson Tatum on Verge of Signing Richest Contract in NBA History With Celtics

With Horford’s return confirmed by Grousbeck, the Celtics appear all but certain to bring back the top six players in their rotation.

Finals MVP Jaylen Brown signed a deal that keeps him on the team through 2028. Jrue Holiday has also signed an extension through 2027. And Jayson Tatum and Porzingis are each under contract through 2025.

Furthermore, Adrian Wojnarowski of ESPN reported Monday night on NBA Countdown that Boston will soon offer Tatum the largest deal in league history — one that will keep him in a Celtics uniform through the end of the decade.

“Once these NBA Finals are over, the teams are now allowed to start negotiating contract extensions and negotiating with their own free agents, which means that the Celtics will soon present Jayson Tatum with the largest contract extension in NBA history — a five-year, $315 million extension,” Wojnarowski said.

That leaves only Derrick White to consider, though he remains under contract through next season on a four-year deal worth $70 million that pays him north of $20 million for the 2024-25 campaign. Talks of an extension between White and Boston could begin as early as this summer.