Kristaps Porzingis is personally excited about the NBA’s inaugural In-Season Tournament, but when asked Friday if it’s a topic of conversation within the Celtics locker room, the big man paused before revealing the truth.

“Honestly? No,” Porzingis said with a smirk.

The Celtics began in-season tournament play Friday at TD Garden with their first game of group play against the Nets, and they’ll play three more games in their group over the next three weeks – at Toronto on Nov. 17, at Orlando on Nov. 24 and home against Chicago on Nov. 28. The winners of the six groups across the league plus two wild-card teams will advance to the quarterfinal knockout round before the semifinals and championship that will be played in Las Vegas.

All in-season tournament games except the championship game will count toward the regular season standings. The in-season tournament idea – which is common in European sports leagues and especially in soccer – has been met with a mix of excitement and skepticism. Jaylen Brown said last week that it’s good for extra revenue for the league and to create some interest for early-season games that have historically drawn lower ratings, but didn’t seem particularly excited about it.

Celtics coach Joe Mazzulla said the tournament isn’t something he addressed with his players.

“To me, it’s one of 82,” Mazzulla said. “There is obviously something that we’re trying to create here in the NBA which I think is important. I do like the structure of in-season tournaments in soccer internationally and so I get what we’re trying to get to. I think it can be a good thing. But the way it’s set up right now, it’s still one of 82 and regardless if this was an in-season tournament game or not, we’re playing to win the game, and so that’s kind of the process that we’re going with. And so, we appreciate it but you have to win regardless.

Even the optimistic Porzingis admitted there’s an element of the unknown.

“It’s probably going to be a bit more exciting for the fans, but I think the thing is, a lot of people don’t know what it is,” Porzingis said. “Maybe if it’s a successful year, which I believe it will be this year, next year every game is going to be like OK, now we know what it is. So I think now, we’re going into something that we don’t know, but for us, it’s important to win every game.”

The Celtics debuted a special court designed for the tournament that included a dark green color covering most of the floor. The C’s also wore their “City Edition” uniforms for the first time this season. It included a “BOSTON” wordmark on the front of the white jersey that takes inspiration from the façade of the Springfield YMCA as the Celtics paid homage to the birthplace of basketball. The Celtics will wear their “City Edition” uniforms 15 times this season.

The redesigned court is seen before the NBA basketball in-season tournament game between the Boston Celtics and the Brooklyn Nets, Friday, Nov. 10, 2023, in Boston. (AP Photo/Michael Dwyer)

Horford misses game vs. Nets

Al Horford missed Friday’s game against the Nets due to what the Celtics described as “right knee injury management.” Mazzulla said Horford experienced some soreness after Wednesday’s loss to the 76ers and he’s hopeful he’ll return for Saturday’s home game against the Raptors.

Horford did not play both games of back-to-backs last season, and that doesn’t appear to change this season for the 37-year-old big man. Horford, however, typically rested on the second game of back-to-backs last year, so sitting out the front end of this weekend’s back-to-back – the first of this season – represented a change.

The Celtics managed Horford’s workload last season to ensure he was fresh for the playoffs – he played 63 games and averaged 30.5 minutes per game – but still seemed to slow down in the Eastern Conference Finals. Horford is now in a bench role for the C’s and has averaged 24.1 minutes in his first seven games. He’s been sound defensively but has started slow offensively, shooting just 22.7 percent from 3-point range.

Porzingis said he expects to play both games of this weekend’s back-to-back. The big man – who missed the FIBA World Cup this summer due to plantar fasciitis – has continued a healthy run after playing 65 games last season. He’s still working his way back to full physical shape after missing that time this summer.

“I think last year, I added a few things to my routine and stuff that I have been doing now. Honestly, I didn’t start the season in like, perfect shape,” Porzingis said. “I feel like now, the last couple games, I’m starting to feel like the way I need to feel on the court. I’m still going to improve. Rhythm, everything, just feel, shot, everything is still going to get much better. Outside of the games, my routines are more or less what I did last year, maybe adding a couple more things from the Celtics medical staff. It’s been working great for me.”

Like what?

“I’m a big lunge guy,” Porzingis said. “I do lunges before every game, kind of gets my legs going.”

Tip-ins

Robert Williams will undergo season-ending right knee surgery, according to a report Friday from ESPN, another devastating blow to the former Celtics center’s injury-plagued career. Williams – who was traded to the Blazers prior to training camp in the Jrue Holiday deal after five seasons in Boston – played six games with Portland before suffering a right knee injury last Sunday against the Grizzlies.

Williams is expected to be ready for the start of the 2024-25 season. He missed some of the 2022 playoffs and the beginning of last season with the Celtics due to a torn meniscus in his left knee. …

The Celtics wore warmup shirts that said “Raise the Age” on the front for Friday’s game to raise awareness for a bill to gradually raise the age of juvenile jurisdiction to include 18-20 year olds.

“I think it’s important in general, not just the organization but for humanity,” Mazzulla said. “My wife worked, she was in criminal justice and she was a probation officer and we saw sometimes how the system can put people back and how it can hold people back and put them in even tougher situations and where they’re at, and so this bill is important to a lot of people because of what it can offer.” …

Nets leading scorer Cam Thomas, who is averaging 26.9 points per game, was out Friday due to an ankle sprain. He’s expected to miss about two weeks.