Celtics' Marcus Smart out of Game 4 vs. Heat with ankle sprain

The Boston Celtics will be without Marcus Smart on Monday night.

Smart was officially ruled out of their matchup with the Miami Heat due to an ankle sprain, the team announced about an hour before Game 4 of the Eastern Conference finals. Jayson Tatum and Robert Williams, however, were cleared to play.

Smart went down with what looked like a very severe ankle injury in the third quarter of Miami’s win in Game 3 of the series on Saturday night. Smart rolled his ankle hard right after halftime while trying to grab a rebound, and his ankle then went under Heat guard Kyle Lowry as they both fell to the ground. Smart yelled out in pain instantly while grabbing at his leg as play stopped.

He was helped off the court and moved very slowly back to the locker room.

Smart returned to the court just minutes later, however, and finished out the game. He finished with 16 points and seven assists. Smart — who has averaged 15.8 points and 6.8 assists so far this postseason — had been listed as questionable for Monday’s game. He also missed Game 1 with a right midfoot sprain as Miami opened the series with a 118-107 win.

Though Smart didn't see the court, the Celtics had no problem whatsoever on Monday night. Boston cruised to a dominant 102-82 win in Game 4 to even up the series after a massive defensive showing. The Heat scored just 11 points in the opening quarter and started the game missing 14 consecutive field goals.

Game 5 of the series is set for Wednesday night in Miami.