Celtics Coach Joe Mazzulla said there are plenty of reasons not to call a timeout at the end of games, but felt he should have at the end of overtime of Boston’s Game 4 loss to the 76ers on Sunday in Philadelphia. Matt Slocum/Associated Press

Coach Joe Mazzulla has trusted and empowered his players all season to make plays on the fly in late-game situations instead of calling a timeout. But with the benefit of hindsight, he would have changed his approach for the final play of overtime that cost the Celtics in their Game 4 loss to the 76ers.

The Celtics trailed by one with the ball and 18 seconds to go in overtime on Sunday. Mazzulla didn’t call a timeout, and the Celtics ultimately didn’t even get a shot off because they were too slow in their actions. Jayson Tatum found Marcus Smart for a 3-pointer that went in, but he released it after the buzzer.

A day later, Mazzulla explained his thinking on the play before admitting he should have called a timeout.

“It’s something we’ve talked about all year. I trust our guys to make the right play,” Mazzulla said Monday. “Prevented a team from getting matchups off the floor, prevented a team from getting their defense organized. Hindsight is always 20/20, so it sounds good to say, ‘Yes, we should’ve 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 to give them an opportunity, too.

“At the end of overtime, hindsight’s 20/20, I should have called it to help us get a two-for-one or get a couple more possessions. Obviously with 14 seconds left, down one, you want to get as many chances as you can. So, definitely learned from that.”

The situation at the end of regulation was different. The game was tied as the final seconds ticked off and the Celtics ended up getting a great look as Tatum found Smart for a wide-open 3-point attempt at the buzzer that bounced off the rim. But trailing by one late in overtime, Tatum waited until there was less than five seconds left before starting a pick-and-roll action with Derrick White, and Smart’s game-winning attempt was a half-second too late.

“I waited a second too late,” Tatum said after the loss.

Mazzulla said he should have recognized that his team was going too slow on the play and acted on it. If the Celtics took a shot sooner and missed, they would still be down by three points at most for a second possession after forcing the Sixers to shoot free throws, leaving them with an opportunity to at least tie the game and send the game to a second overtime.

The situation left the first-year coach with several lessons to learn.

“Obviously if it doesn’t go well, it’s a mistake,” Mazzulla said. “And so, I think the two lessons that you learn from that are, call it right away, get a two-for-one, get two shots and a couple extra possessions, or we have to have the 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, but in that standpoint, once we’re losing pace, I gotta call it so we can get a shot up earlier.”