BOSTON -- Although the Boston Celtics emerged with a 106-99 victory Wednesday night against the Philadelphia 76ers, their focus afterward was on Jaylen Brown's well-being after the All-Star guard left late in the first half because of a facial injury suffered on an inadvertent elbow from teammate Jayson Tatum.

"He was quiet," said Celtics guard Malcolm Brogdon, who started the second half for Brown and finished with 19 points, five rebounds and three assists. "He was in a lot of pain. Just told him to feel better.

"There was nothing I think we could do for him. But he was in a lot of pain when we left.

"We'll pray for him."

Brown came up short on a corner 3-point try and chased after the rebound along with Tatum, whose right elbow caught him on the left side of his face. Brown immediately went down in clear pain and exited for the locker room with 1:27 to go in the second quarter.

At halftime, Boston ruled him out for the rest of the game because of a facial contusion. While the team didn't say how long he could be sidelined, there was concern he could miss time with the injury.

"I hope he's all right," Tatum told ESPN's Cassidy Hubbarth after the game. "We both went for the rebound, collided ... just a freak accident. I feel terrible. So, I just hope he's going to be all right."

Celtics coach Joe Mazzulla said after the game he tried to reach out to his star guard but was unable to do so.

"I haven't gotten an update yet," Mazzulla said. "I called him and he didn't answer, but I'll get that ASAP. I hope he's OK."

Fellow Celtics starters Al Horford, Marcus Smart and Robert Williams didn't play at all because of injury. Horford (knee soreness) and Williams (ankle sprain) were game-time decisions before both being ruled out, and Smart has been sidelined since Jan. 21 because of an ankle sprain.

Their absences didn't matter much in this battle of Eastern Conference rivals, however, as Boston shot a blistering 54.3% (19-for-35) from 3-point range and outscored the 76ers by 27 points from behind the arc. It also had a 41-21 advantage in bench scoring.

As a result, the Celtics were able to win despite Tatum finishing with a pedestrian line -- 12 points, eight rebounds and nine assists with four turnovers on 5-for-15 shooting in 37 minutes.

"It just shows our ability," said Grant Williams, who started in place of Robert Williams and finished with 15 points, eight rebounds and five assists in 39 minutes. "Everybody stepped up tonight. [Tatum] did a phenomenal job. When they tried to take him out of the actions, he did a phenomenal job of getting other guys involved. That's what MVPs do. Even when necessarily they're not getting 30 points a night and everything like that, they still impact winning. And that's what he did tonight.

"And then you have guys like Malcolm, [Derrick White], especially Blake [Griffin], Payton [Pritchard], down the line, Sam [Hauser], stepped up and just knocked down shots and also played with confidence, played on the defensive end and made everything tough. And we did a good job of not only limiting those two stars [Joel Embiid and James Harden] but also the other guys, too, like Tyrese [Maxey] and those guys. So they did a great job tonight."

Philadelphia left frustrated after dropping a second straight game. It previously had gone 22-5 over a 27-game stretch.

"It's very disappointing, very frustrating," Harden said. "Especially coming off a loss the way we played [against the Knicks] in New York, it was an opportunity to have a good bounce-back game, and we didn't do it.

"We got to find a way to close out the games before the [All-Star break]. We've got a handful of them left, so whatever it takes."

The 76ers have lost to Boston twice at TD Garden this season. The teams have two more matchups slated to take place in Philadelphia on Feb. 25 and April 4, the final week of the regular season.

"Right now, Boston has beaten us twice," 76ers coach Doc Rivers said. "Boston won the East last year. Boston is the best team in the East. I said that before the game. It's our job to prove that wrong, but we have a lot of time to do that."