NEW YORK >> Jayson Tatum spoke calmly as he addressed reporters at Madison Square Garden on Saturday evening. It was the same demeanor he projected two days earlier, though the events preceding his sit-downs were drastically different.

After he played poorly in the Celtics’ calamitous Game 2 loss to the New York Knicks at TD Garden, Tatum acknowledged his struggles with even-keeled confidence. He proceeded to deliver a much more effective performance in Game 3, tallying 22 points, nine rebounds, seven assists and two steals as Boston breezed past New York 115-93 to avoid an 0-3 deficit in the best-of-seven Eastern Conference semifinals.

Throughout his career, Tatum has faced criticism for his perceived lack of a killer instinct. Even his own father has publicly called for the six-time All-Star to be more of an “a—hole.” He was the subject of fierce scrutiny on debate shows and talk radio after he shot 28.8% from the field and 5-for-20 from 3-point range in Games 1 and 2 against New York, both of which featured blown 20-point leads by Boston.

Tatum, though, views his mental balance as a strength, as he explained in a candid response after Saturday’s sorely needed win.

“You just understand what comes with being that guy,” he said. “I live a great life, I ain’t going to lie. I make a lot of money, I take care of my family, I’ve been able to experience a lot of things, but you also have to accept what comes with that, right? I get a lot of praise. I get a lot of credit. I get a lot of accolades. But I’m not perfect, and there’s times where I’ve needed to play better. I’ve needed to do more. And that comes with being that guy.

“So, just understanding that, and people just don’t criticize me. There’s a lot of people that came before me that they criticized, and there’s going to be people that come after me that they criticize. For me, it’s just a sense of joy that I play with. Coming into a game with an angry face and mad at the world, that’s not who I am. It’s not when I play my best. So I always say you’ve got to be the same person if things are going great and when things aren’t going great. You can’t switch up. That’s the character of a good man.”

Tatum went 5-for-9 on 3-point attempts in the win, headlining a significantly improved Celtics effort from beyond the arc (20-for-40).

Porzingis comes off bench

The Celtics removed Kristaps Porzingis from their injury report Saturday — a positive sign for the big man as he battled symptoms from the viral illness he’s dealt with since February — but opted to bring him off the bench for the second straight game. Al Horford again got the start alongside Derrick White, Jrue Holiday, Jaylen Brown and Tatum.

Before this series, Porzingis had come off the bench just four times in his 10-year NBA career.

“He’s gotten better,” Celtics head coach Joe Mazzulla said pregame. “He felt better yesterday. I haven’t talked to him today yet, so we’ll see how it goes. But he’ll give it a go, and we’ll see where it goes from there.”

Porzingis’ shooting struggles persisted in Game 3 — after an 0-for-3 showing, he’s now shooting 33% from the field and 15.8% from three this postseason — but he was impactful as a rim protector with three blocks and four rebounds. The Celtics outscored the Knicks by 11 points over his 19 minutes, the best mark of any bench player.

“He gave us some good stuff,” Mazzulla said. “Both ends of the floor, rim protection, his screening offensively — everybody got some good stuff out of that. I appreciate him, keep battling through.”

ESPN’s Shams Charania shared additional details about what Porzingis is battling through during the network’s pregame coverage, though the exact nature of his illness has not been reported.

“He felt that he had actually turned a corner right as the playoffs started in mid-April, but in his own words, he had a crash right before Game 1 of this series,” Charania said. “He’s tried a lot of different things to try to mitigate the side effects. I’m told he’s been receiving IVs, immune boosters, he’s even changed up his sleep patterns to try to get more rest. He’s essentially waking up every day hoping and praying that he feels better.”

Hauser sits again

Boston downgraded bench sharpshooter Sam Hauser from doubtful to out ahead before Saturday’s game.

It was the second straight DNP for Hauser, who sprained his right ankle during the Celtics’ Game 1 loss at TD Garden. He traveled with the team to MSG and did not have a visible limp when he entered the arena, but the team evidently determined he was not fit to play.

Hauser was the Celtics’ most efficient 3-point shooter during the regular season (team-best 41.6% from beyond the arc) but has been quiet this postseason. Over six playoff appearances before his injury, he totaled 16 points on 13 field-goal attempts and was held scoreless four times.

At least one rotation player has been inactive for six of Boston’s eight playoff games, with Tatum sitting out Game 2 of its opening-round series against Orlando and Holiday sitting out Games 3, 4 and 5 against the Magic.

Despite those absences, Mazzulla hasn’t pulled any of Boston’s deep reserves into his rotation. Lower-tier subs like Torrey Craig, Baylor Scheierman, Neemias Queta, Jordan Walsh and JD Davison only have played in garbage time since the playoffs began.

Marquee matchup

Saturday’s matchup was billed as the most anticipated Knicks home game since the 1999 NBA Finals, as New York had an opportunity to pull within one win of its first Eastern Conference finals berth since 2000.

Seats in the nosebleeds were selling for upward of $600 on the secondary market, and the crowd was packed and rowdy well before tipoff.

Knicks head coach Tom Thibodeau tried to downplay the raucous atmosphere in his pregame presser.

“We certainly appreciate our fans and being home and all that, but the playoffs, each game’s different, and you have to earn your wins,” Thibodeau said. “So don’t get lost in the emotion of the game. Concentrate on what it’s going to take to win the game and just focus on the game.”

The crowd’s passion quickly dissolved into nervous energy, then resigned disappointment once it became clear that a third straight unlikely comeback was not in the cards. The Celtics led by 20-plus points for the entire second half, and fans began streaming toward the exits with five minutes remaining.

Game 4 is Monday night at MSG.