O'Neal deemed himself "tired" after a spirited two-hour session, but suggested he's optimistic his sore left hamstring will respond well enough to allow O'Neal to participate in his first action of the exhibition season Sunday.
Celtics coach Doc Rivers dubbed him a game-time decision.
"I'm tired today, but you gotta start somewhere," said O'Neal. "I've gotta be able to build. My hamstring felt good, it felt really good. I'm looking forward to getting back on the court since I haven't been able to play with guys in the real uniforms yet."
O'Neal admitted he's been eager to get to work with his new teammates outside of the practice gym, but recognized why the coaching staff didn't want him to rush back, particularly early in the preseason. He did note that the play of Boston's backup centers like rookie Semih Erden have made it easier to watch from the sidelines already because there isn't a substantial drop off in talent, which is one of the reasons he ultimately signed with Boston this offseason.
Boston's starters were excited to get another look at O'Neal with the first team.
"It was very good having JO back out there," said Kevin Garnett. "If we’re going to be anything this year, we’re going to need his contributions."
Added Paul Pierce: "He looked good, running up and down the court, getting acclimated to the things we're trying to do. He hasn't played a preseason game yet, so it'll be nice to see how he works out there with us."
Also practicing Saturday was rookie Avery Bradley, who has been idle since offseason ankle surgery in July, and Delonte West, who left Thursday's exhibition win over the New Jersey Nets in the second half with tension in his lower back (West had previously missed a practice session last week with back spasms). While he wasn't particularly happy with himself based on how he practiced, West is expected to play Sunday barring a setback overnight.
As usual, he was one of the last players off the court after extended running and shooting after the session.
"[West] went through the whole practice," said Rivers. "I think he'll play."
As one center returned, another got a break as Shaquille O'Neal sat out Saturday's practice.
"It's just his hips," said Rivers. " That will be an issue on and off at times [throughout the season]. He got rest today."
Which was good news for guys like Erden.
"We got tried of Shaq beating up all of our centers, so we gave him the day off," joked Pierce. "[The Celtics got Shaq] in the weight room, just worked out, get his body right. It was a chance to get Jermaine back on the court today, which is a plus for us. It's the preseason, we can take caution with our bigs. Today was a good day for him to rest."