Boston Celtics guard Payton Pritchard (11) drives to the basket...

Boston Celtics guard Payton Pritchard (11) drives to the basket past Knicks guard Immanuel Quickley (5) during the first half of an NBA basketball game, Friday, Dec. 8, 2023. Credit: AP/Charles Krupa

BOSTON — A creature of habit, Tom Thibodeau changed his starting lineup Friday night, replacing Quentin Grimes with Donte DiVincenzo one game after Grimes voiced his frustration with his role as a starter.

So what’s the next move?

While Grimes did seem to shake off his struggles with more chances as part of the second unit, the Knicks appeared just as outclassed by the Celtics as they had by the Bucks on Tuesday night. One game after allowing 146 points, the Knicks fell to Boston, 133-123, at TD Garden.

“It’s problematic,” Thibodeau said. “We’ve got to fix our defense. It starts individually. Better containment of the ball. Better ball pressure. Better challenging shots. And every aspect. I thought offensively guys did a good job trying to create advantages. The rebounding is good. But our defense has to be fixed. “

The Knicks may have encountered another issue; Mitchell Robinson had X-rays of his left foot at halftime. He returned to the bench and the game 3:43 into the third quarter, but after playing 4:49 and not moving well, he was pulled with 3:28 left in the third and did not play again.

And Jalen Brunson left the court and headed to the locker room after stepping on Payton Pritchard’s foot with 21 seconds left and the game out of reach.

Robinson said afterward that he thinks he is fine, and Thibodeau said it was precautionary because Robinson had been unable to warm up on the court before the second half. Brunson left the arena without speaking with the media and Thibodeau said he did not have an update.

Thibodeau would not entertain a question about having Brunson on the floor after the Celtics pulled their starters shortly before the injury.

“I didn’t see what happened with him,” said RJ Barrett, who suffered a sprained ankle in a similar late-game situation two years ago. “I remember mine was a little freak play, my foot just got caught, tangled . . . Those things happen. It could have happened in the first quarter. Ended up happening at that time.”

The Knicks (12-9) trimmed a 20-point deficit to 119-112 in the fourth quarter as the Celtics (16-5) mildly imploded, with Jaylen Brown ejected with a pair of technicals. After a missed three-pointer, Sam Hauser outhustled the Knicks to the loose ball, leading to a second-chance bucket for Derrick White. After another Knicks miss, White added two free throws and Boston’s lead was back to 11.

White led the Celtics with 30 points. Jayson Tatum added 25 and Kristaps Porzingis had 21 after hitting his first seven shots.

The Knicks are 2-9 against teams with winning records and 10-0 against sub-.500 teams. And with the In-Season Tournament adding road games in Milwaukee and Boston this week, that means the Knicks will play each of these Eastern Conference powerhouses five times this season, which looks like a task outside of their level.

While the lineup change may not have been the solution that Grimes hoped for when he voiced his frustration about lack of opportunities, he did respond well with much more offensive activity. After scoring only six points in his previous three games, Grimes had eight points in nine minutes in the first half and finished with 13 points in 19:23. Brunson and Barrett had 23 points each and Julius Randle added 20. DiVincenzo scored six points in 22:26.

But the Knicks’ problems against elite teams went deeper than shifting pieces on the fringe of the starting lineup. The Knicks allowed the Bucks to put up video game-type numbers Tuesday, piling up 146 points. They followed that by surrendering 74 points in the first half and 109 through three quarters, making it 255 points in a seven-quarter span, with at least 33 in each period.

“Our commitment level, intensity, recovering to the three-point line, all that stuff,” Randle said. “Yeah, it’s a trend the past few games, so we’ve gotta address it and we’ll be all right.”

Notes & quotes: Isaiah Hartenstein tied his career high with 16 rebounds . . .  Brown's ejection was the first of his career. "I wish I would have gotten my money's worth. I always thought my first career ejection would be something a little more exciting, maybe a tussle or something," he said. " . . . Not some overemotional ref who had a bad day. What I'm most upset about, I should have gotten my [expletive] money's worth . . .  I ain't gonna comment on officiating in general, but I am going to comment on this guy in particular. I thought that was [expletive]."

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