BOSTON -- The Celtics will be without the 2021-22 NBA Defensive Player of the Year on Tuesday night, as the team ruled Marcus Smart out of Game 2 of their Eastern Conference semifinal series against the Milwaukee Bucks because of a right quad contusion.

Smart initially hurt the quad in the first half of Game 1 on Sunday but came back. He then took back-to-back shots to the right leg in the third quarter.

"It's a little bit of both, swelling and pain, restricted movement," Boston coach Ime Udoka said at his pregame news conference. "Some limited movement that didn't get better over the days like we thought it would."

With three days off between Game 2 and Game 3 in Milwaukee on Saturday, Udoka expects Smart to be better by the time the Celtics take the floor again after Tuesday's game.

Udoka added that Derrick White will start in Smart's place.

"I think he does a lot of things well. Obviously, it's hard to make up for Marcus specifically for what he does for our team," Udoka said.

"Derrick is another big guard that you don't lose a lot as far as size and versatility defensively. Then offensively, he's very capable of scoring, running plays and getting guys the ball. The beauty of having him is he checks a lot of those boxes.

"There's not a lot of drop-off with Derrick in there other than the toughness that nobody really brings that Marcus has."

When Smart exited the game in the third quarter, he needed to hit the exercise bike before checking back in with 8 minutes, 37 seconds left in the fourth quarter. He played until Udoka took out his starters with 1:59 to go in the 101-89 loss.

In 33 minutes, Smart finished with 10 points and six assists.