BOSTON — Joe Mazzulla has not been a coach who likes to throw in the towel throughout his tenure as Celtics coach. However, a dismal second half by the Celtics in Game 2 on Thursday night led to Mazzulla pulling the plug on his starters with five minutes remaining in a 118-94 blowout defeat to the Cavaliers.

A flagrant foul by Jayson Tatum pushed the Celtics’ deficit to 24 points with five remaining remaining in regulation, capping a 17-45 run by the visitors. With Boston facing scattered boos from the Garden crowd later in the second half, Mazzulla waived the white flag by inserting five deep reserves into the game.

When Mazzulla was asked about the decision after the loss, the Celtics coach signaled the choice was more about the future than sending a message to his starters.

“I mean, I just felt like that was the best thing to do at that particular time,” Mazzulla said. “We have another game coming up soon.”

Mazzulla deferred when pressed about whether it was a night that the starters clearly didn’t have it.

“I thought that was the best thing to do at that time,” Mazzulla said. “I didn’t think it was that early.”

Boston suffered through one of their worst shooting nights of the season in the defeat, hitting just 22.9 percent of their 3s including 0-of-8 in the game-changing third quarter. Those struggles could have led to some bad habits re-emerging for Boston as the defensive effort waned as the Cavs shooting improved.

“I don’t know if it’s creeping back in, but I definitely think there were times in the game where we went through tough stretches offensively that affected our defense,” Mazzulla admitted.

Jaylen Brown was more blunt when assessing the team’s defense.

“I think it was just a bad game,” Mazzulla said. “Obviously we didn’t shoot the ball very well tonight, but defensively it was an unacceptable performance, and I think that’s where we look at that and I’m the most upset. Defensively we gave up 118 points, and on top of that we lost the rebound battle. So we didn’t help ourselves tonight.”

The Celtics won’t have much time to regroup before heading to Cleveland for a pivotal Game 3 on Saturday night but Brown is confident this group will bounce back like they did after their Game 2 loss to the Heat.

“You learn from it,” Brown said. ‘Take it on the chin, you learn from it, and you come out and put your best foot forward for the next game. Obviously, this was an unacceptable performance. We need to be ready to respond.”