One O'Neal is already back with the Celtics, and now the other is not far behind. Celtics president of basketball operations Danny Ainge says that the 39-year-old Shaquille O'Neal should return to action either Sunday or Tuesday.

"I was just with Shaq, we were just working out down in Waltham," Ainge said on WEEI's The Big Show on Thursday afternoon. "Shaq is either going to play Sunday or Tuesday."

O'Neal has been out for the last two months with an inflamed Achilles. He's played in only 36 games this season, and only three since Jan. 21. Ainge and Doc Rivers are planning to have him back at full strength before the playoffs.

"With Shaq on the court this year, in the games he started for us, our offense and our defense has been better than it’s been for four years," Ainge said. "That tells you how important Shaq is, how important his presence is alone."

The Celtics return home from their road trip to play the Detroit Pistons at the TD Garden on Sunday, followed by the Philadelphia 76ers on Tuesday. If Shaq makes his return in one of those two contests, that should give him six or seven regular-season games to tune up before the playoffs.

The Celtics' other veteran center, Jermaine O'Neal, is set to return Thursday against the Spurs. He's been out since Jan. 10, recovering from knee surgery.