BOSTON -- Boston Celtics captain Paul Pierce suffered a left knee injury during shootaround on Sunday, which initially left his status unclear for Game 4 of an Eastern Conference quarterfinal series against the Atlanta Hawks

Pierce was able to suit up, only to aggravate the injury in the first half. He admitted his status moving forward is uncertain, though he hopes to play in Game 5 in Atlanta on Tuesday.

Pierce admitted his knee felt "sore" and "tender" after the Celtics posted a 101-79 triumph over the Hawks at TD Garden. He played a mere 16 minutes, 37 seconds, but chipped in a game-high 24 points on 10-of-13 shooting to spearhead Boston's offensive outburst.

The Celtics lead the best-of-seven Eastern Conference quarterfinal series 3 games to 1.

"I kinda sprained it this morning, then I aggravated it today in the game," said Pierce. "I’m glad we were able to get a win like this, give me some rest. We'll get me a couple days off, I can get some treatment and hopefully it feels good on Tuesday."

Boston engaged in a light walk-through Sunday morning, but still nearly lost Pierce. He then aggravated the injury when he banged knees with Atlanta's Josh Smith with 5:45 to play in the first half. He returned to play the first 3½ minutes of the third quarter and helped Boston open a 35-point lead before calling it a night. Pierce spent some time on the exercise bike courtside, then returned to the locker room in the fourth quarter for treatment.

"I kind of tripped over someone’s foot, turned the knee [in shootaround]," said Pierce. "I had to sit around the last half of shootaround and, tonight, I just kind of re-aggravated it when I came up off the double screen with Josh Smith there. It’s a little bit sore right now, so Doc just wanted to take precautions tonight, especially when we had such a big lead. That allowed me to go back in the fourth quarter, get treatment and rest for the next couple days."

Rivers admitted that when he left the shootaround, he wasn't certain the team would have Pierce.

"When I left shootaround, I probably thought he was not going to play," said Rivers. "And [team trainer] Eddie [Lacerte] said, ‘Let’s see, let’s give it a try, and see how he feels.’ I talked to [Pierce] right before the game, I asked him, ‘What do you think?’ And he said, ‘Well let me just try to warm it up and see how I feel.’

"It’s amazing. I mean, honestly, guys around the league [getting injured]. He was just dribbling the ball and went to the floor in shootaround. And I was thinking, ‘What more can you [endure]?’ We were walking. That’s how you felt, like, 'My gosh!' And, honestly, when he went down, it didn’t look good. So the fact that he could come in and play, and then play the way he played was great."

Asked about Pierce's status for Game 5, Rivers said the team will take a wait-and-see approach.

"I have no idea," said Rivers. "With a couple of guys, actually three of them, we literally don’t know. So we’ll find out.”

Rivers was likely referring to Pierce, Ray Allen (ankle), and Avery Bradley (shoulder), who were all essentially game-time decisions based on their ailments heading into Game 4.