Brooklyn guard Kyrie Irving, left, was a star on the Celtics when Jayson Tatum was new to the league. Now a seasoned Tatum and the Celtics face Irving and Brooklyn in the first round of the playoffs starting on Sunday. Steven Senne/Associated Press

BOSTON — Kyrie Irving will likely hear the boos once he steps foot in TD Garden on Sunday, just like every other time he’s played in Boston since he left the Celtics.

It’s another playoff series between Boston and Brooklyn, and former Celtic Irving will be among the top subplots. That’s not too surprising. Irving, who played for the team from 2017-19, hasn’t quite helped his case, whether it was calling Boston fans a “scorned girlfriend” this season or infamously stepping on “Lucky the Leprechaun’s” face after Game 4 of last year’s playoffs.

But his former teammates have been plenty complimentary of Irving, including Jayson Tatum. While Tatum’s the face of the franchise, he was just a rookie teenager trying to learn about the league when they joined forces for the first time in the 2017-18 season. Tatum said they’ve talked about Irving’s time in Boston – and how Irving said he likely could have done some things differently.

“We’ve talked and there are some things that he probably told me he wished he would have done differently,” Tatum said Wednesday. “But I think that’s a part of life. No one is perfect, you just got to move on from it as you get older.”

The Celtics will take on the Nets in the postseason for the second straight year after Brooklyn beat Cleveland in the play-in tournament on Tuesday night to secure the No. 7 seed. While Boston fans will focus their jeers for Irving, the Celtics will have a handful on the court when Irving combines with Kevin Durant and the rest of the Brooklyn roster.

There could be some more Irving vs. Boston juice that comes from the series, but he praised the Celtics when asked Tuesday night about playing them. He pointed out Tatum, Jaylen Brown and other former teammates, adding how difficult they will be to guard and play against.

The Celtics and Nets open the first-round series at 3:30 p.m. Sunday at TD Garden.

“He helped me out a lot those first two years, just kind of watching a superstar,” Tatum said of Irving. “I got to see him every day, see how he worked from his body, prepare for games and things like that. Learned what to do and learned some things what not to do. He will be the first to tell me that I could learn from the encounters that we had.”

BRUCE BROWN’S words were not missed.

Boston Coach Ime Udoka knows a tall task awaits the Celtics’ defense as they try to contain two of the best offensive scorers across the league in Irving and Durant in their upcoming first-round series. That challenge is even tougher with starting center Rob Williams injured for the matchup.

However, Udoka fired back at comments from Brown, a forward with the Nets, about Brooklyn targeting the middle with Al Horford and Daniel Theis manning the back line.

“We still have two high-level defenders back there, big guys with Daniel and Al, and we have layers to our defense,” Udoka said Wednesday after practice. “So it’s not like we’re getting blown by and Rob is protecting, we still have Marcus, Jaylen, Jayson and everybody else in between.

“We know how he scores and how he attacks in a lot of drop situations. Well, we can take that away by how we want to guard. And so they think it’s attack time because Rob’s out? Obviously we played quite a few games without him now and have done good enough beating some good teams.”

Brown turned some heads earlier this week with his criticism of Boston’s defense without Williams.

“I mean, we can’t let Tatum get 50,” Brown said. “We got to be physical with them. Now they don’t have Robert Williams so they have less of a presence in the paint. We can attack Al Horford and Theis. Them not having Rob Williams is huge.”

The Celtics are 4-3 since Williams suffered his injury but several starters were rested in two of those losses on the second half of back-to-back matchups. On the season, Boston went 11-10 in games Williams did not play. Boston has a 99.9 defensive rating when Williams has been on the court this year. That drops to 104.3 when the starting center is sidelined.

Brown’s own teammates attempted to downplay the comments by Brown after hearing them following Tuesday’s win over the Nets.

“We respect our opponents,” Durant said. “We don’t need to talk about what we’re going to do them. I just don’t like that. But that’s just how Bruce is, he comes in and he keeps the same energy throughout the whole season. But we don’t need to say (expletive) like that, let’s just go out there and hoop.”

The Celtics will have their full lineup available for the matchup outside of Williams, who continues to progress well in his rehab, according to Udoka.

“A little bit more every day,” Udoka said of Williams’ recovery. “He’s looking good and in good spirits, like I’ve said from day one. Getting out on the court doing some shooting drills and touch work there. And so we’re happy with the progress, but at the same time, we understand it’s gonna take time.”

CHARLES BARKLEY certainly likes Boston’s chances against the Nets

“There’s no way they can beat the Celtics,” Barkley said. “They got two great players. They both actually played as good as they probably can play (on Tuesday). Kevin Durant was fabulous with his passing and his defense. Kyrie was great. But other than that, I know they can’t beat the Celtics now.

“All these fools on these other morning talk shows can let this ship sail. Both of those guys played great – great – and they barely beat a mediocre Cavs team.”