Did the Celtics err by putting Marcus Smart back in Sunday’s game after his injury?

Marcus Smart is expected to be sidelined from 4-6 weeks, although one league source said there is some optimism that it could be a 3-5 week recovery time.Matt Slocum/Associated Press/Associated Press

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With just under seven minutes left in the third quarter of the Celtics’ loss to the Magic on Sunday, guard Marcus Smart saw an opportunity for a steal under Orlando’s basket, and it was little surprise that he went for it.

Smart deflected the ball, but then ran into Orlando’s hulking, 260-pound All-Star center, Nikola Vucevic. The Celtics guard dropped to the ground in pain, unaware that he had suffered an oblique tear that is expected to sideline him for at least Boston’s opening-round playoff series against the Pacers, and perhaps longer.

On one hand, it was a fluke injury involving one of the most fearless players in Celtics history. But the chain of events that followed also ignites questions about whether the team could have done more to protect Smart.

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Smart was on the floor, wincing and writhing for a few moments before ultimately getting up and walking to Boston’s bench during a timeout. He took a seat on a padded folding chair during the break and told the team’s medical staff that he could keep playing. So he went back into the game.

“You always have to listen to the player,” Celtics president of basketball operations Danny Ainge said Thursday. “You sprain your ankle and say, ‘I can still play. I can still play.’ Sometimes you can’t. Sometimes you go out there and you go, ‘No, I’m hurting the team.’ Or, ‘I’m going to reinjure it.’ So thank goodness he just ran up the court one time and ran back and knew he was not capable of playing. I don’t put any blame on that. You always listen to the players, and you know Marcus was going to try to play if he can, and he couldn’t.”

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Dr. Douglas Comeau, the director of sports medicine at Boston University and Boston Medical Center, said it is common for pain to initially resolve in injuries such as Smart’s, giving a false sense of stability. He said that although Smart’s pain may have then become even more severe, it was not an indication that he’d exacerbated the injury by returning to the court.

“You try to give it a go, but then if the pain worsens, it’s not necessarily making the injury worse,” Comeau said. “It’s whether you can tolerate it.”

But Comeau, who has not examined Smart or seen the results of his MRI, added that a rotation of the oblique could cause further problems with injuries such as this one, so rest will be most important in the coming weeks.

“Really, the tissue needs to start healing,” he said. “If you engage things, if you think about any type of rotation, it could injure it further.”

Celtics coach Brad Stevens said that the team’s medical staff was talking to Smart “the whole time” that he was on the bench during the timeout after he was initially injured. Smart was back on the floor when Al Horford hit a 3-pointer, but it was clear that he was in considerable pain.

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Then as he jogged back on defense, it became too much to bear. He signaled to the bench that he needed assistance, then held his lower back, and then collapsed to the ground once again. He was helped off the court and to the locker room by team medical staffers.

“He said afterward, he told me he didn’t really notice it until he bent his knees and got in a stance,” Stevens said Thursday. “So that’s when it didn’t feel the same. I have to listen to the training staff, I have to listen to our players, and Marcus was the one who gave the thumbs up on that.”

The Celtics found out before the game that they had clinched home court advantage in the first round of the NBA playoffs, so there was really very little at stake Sunday. The team could have erred on the side of caution and simply kept Smart on the bench even though he insisted that he was able to return, but Ainge and Stevens both made it clear that in situations like this, they count on the information they receive from the players.

Boston also could have held Smart and the other starters out of the game completely — much like it did in its season-finale against the Wizards. But that would have left an even larger gap between their last game and the start of the playoffs against the Pacers on Sunday, and injuries can happen anywhere.

“I certainly don’t question Coach Stevens for playing him, either,” Ainge said. “I mean you’ve got to play guys, and it was a good game and good competition. You can’t go for a long period of time without getting reps and getting to play. The plan was to play those guys against Orlando, and leading up to that game we didn’t know if we had home court advantage locked up until right before tipoff. So the guys were prepared and ready to play, and I don’t think Brad was planning on playing Marcus in the fourth quarter. But it happened in the third, and you can’t put him in bubble wrap.

“I remember in 1987 I got hurt in practice leading up to the playoffs, and it bothered me the entire playoffs. I was never the same player. But you’ve got to practice. You’ve got to have contact, and there’s always risk of injury.”

Smart is expected to be sidelined from 4-6 weeks, although one league source said there is some optimism that it could be a 3-5 week recovery time. Either way, there appears to be a chance that Smart could return at some point during a potential Eastern Conference semifinal series.

“This is an injury that requires a little patience at first for it to heal, and then you can progress,” Comeau said. “That’s what’s going to be frustrating for the athlete, and also the people providing him or her care, because you want them to get better right away, and sometimes with this type of injury it doesn’t happen.”