Boston Celtics coach Joe Mazzulla admitted Monday he should have called a timeout before the final possession of his team's 116-115 overtime loss to the Philadelphia 76ers in Game 4, walking back what he originally said about the decision following Sunday's game.

The Celtics inbounded the ball with 19 seconds remaining after a James Harden 3-pointer, but never got a shot attempt off before the final buzzer.

Mazzulla defended the strategy after the game Sunday, but on Monday he acknowledged a timeout could have given the Celtics an opportunity at multiple chances to win the game.

"At the end of overtime, hindsight is 20/20. I should have called [a timeout] to help us get a 2-for-1 or a couple more possessions," Mazzulla said during a conference call with reporters. "So, obviously with 14 seconds left, down one, you want to get as many chances as you can. So we'll definitely learn from that."

The Celtics were faced with the same scenario at the end of the fourth quarter. Harden tied the game on a floater with 16.1 seconds remaining in regulation, and the Celtics inbounded the ball without calling a timeout. Jayson Tatum's drive generated an open 3-pointer from Marcus Smart, who missed as the game went to overtime.

However, Mazzulla stood by his decision-making at the end of the fourth quarter.

"It's something we've talked about all year," he said Monday. "We trust our guys to make the right play. [Not calling a timeout] prevents the other team from getting matchups off the floor. It prevents the other team from getting their defense organized.

"Hindsight is always 20/20, so it sounds good to say, 'Yes we should have done this,' but we've prepared all year as a team to be able to take advantage of those situations. More times than not it worked out for us. I thought the end of regulation it worked out. We got the last shot, which is what you want. You don't want them to get an opportunity too."

Down one at the end of overtime, Tatum dribbled out the clock and did not begin driving toward the basket until there were about five seconds remaining on the game clock. He supported his coach's decision not to call a timeout at the end of the game but admitted that he should have started attacking the basket sooner.

Tatum recalled how he hit the game-winning layup in the final seconds of Game 1 of Boston's 2022 first-round series against the Brooklyn Nets because the Celtics inbounded the ball without calling a timeout, preventing the opposing defense from getting organized.

"We've been doing it all year, we feel confident in that," Celtics center Al Horford said after Game 4. "The momentum was there. Jayson had the ball in his hands, making a great play and if [Marcus] Smart would've caught it half a second earlier, it would've been down. I'm not getting too hung up on that play."

Mazzulla, a 34-year-old in his first season as head coach, has been giving his players freedom on the final possessions all season without stopping the game with a timeout. And while he stuck to the principles behind that decision-making, he acknowledged there were lessons he could learn from Boston's final possession in overtime.

"I think the two lessons that you learn from that is call [a timeout] right away, get a 2-for-1, get two shots, get a couple extra possessions," Mazzulla said. "Or we have to have a clear understanding as a team that we have to go faster to get a shot. We've done both over the course of the season. We just didn't execute either one in that particular situation."

The series is tied 2-2. Game 5 is Tuesday night in Boston.