BOSTON -- As Donovan Mitchell laid on the ground in pain after tweaking his groin midway through the third quarter, it wasn't clear if he'd be able to keep playing.

But after Cavaliers coach J.B. Bickerstaff called timeout, Mitchell returned to the game to help Cleveland mount a furious comeback against the Boston Celtics in front of a sellout crowd at TD Garden.

Mitchell wound up scoring 44 points in 43 minutes, including nearly 23 minutes in the second half alone, as the Cavs nearly erased a 20-point deficit before losing 117-113.

"We were down 20," Mitchell said when asked what allowed him to play through the pain. "In some of those moments, honestly, you're playing off of adrenaline."

During the timeout, Mitchell said he told Bickerstaff he wasn't sure what would happen if he left the game, thinking he might not be able to return to the court if he cooled off. So he stayed in -- and his scoring heated up. Mitchell almost single-handedly dragged Cleveland back into the game after the break, scoring 29 of his 44 points in the second half, including 19 in the third quarter alone. He kept Boston from putting the game out of reach after the Celtics went off for 41 in the third.

"It was just one of those things -- you just leave me in, and I'll keep going and just try to make plays," Mitchell said. "It's this time of year. Try to win these games, and that was really my mindset. There was just no coming out of the game for me. It was just trying to find ways to make plays and shots started to fall. Ultimately, we've got two days off, get some rest, get it rehabbed and get ready for Detroit."

Mitchell said he felt fine after the game but admitted he didn't know how his body would feel once the adrenaline wore off. He said it was similar to an issue he had at the end of a loss in New York in late January, which forced him to sit out two games.

"We'll see what tomorrow is like, obviously with the adrenaline being what it is," Mitchell said. "But it's that time [of year]. It's that time."

Boston led by as many as 20 points in large part because of the play of Mitchell's All-Star Game teammate, Jayson Tatum, who was having his own hot night. Tatum, who was ejected for the first time in his career Monday in a loss to the Knicks, bounced back in a huge way, finishing with 41 points on 13-for-21 shooting to go with 11 rebounds and eight assists.

Asked what allowed him to bounce back, Tatum smiled and said, "Not listening to you guys."

"It's a long season," he said. "It's 82 games. Nobody has a great day at work every day of the year. Everybody has bad days, I guess. But you've got to take the good days with the bad days. I say it all the time -- never get too high, never get too low. And regardless of what happens, you can't change it. You've got to get ready for the next one and move on."