One step forward, two steps back.

The Boston Celtics will welcome Kevin Garnett back to the floor for Wednesday's game against the Oklahoma City Thunder, but will be without big men Jermaine O'Neal (sprained left wrist) and Chris Wilcox (right adductor strain), according to the team.

Garnett missed the last two games while attending to a family issue, but is back with the team. Both O'Neal and Wilcox were injured in Monday's loss in Dallas and while both are listed as day-to-day, they are expected to return to Boston to be further evaluated.

The Celtics are already without Rajon Rondo (suspension) and Brandon Bass (knee). The losses leave the team extremely shorthanded up front and will force the Celtics to go with a smaller lineup, which might include a starting group of Avery Bradley, Ray Allen, Mickael Pietrus, Paul Pierce, and Garnett (though the Celtics could also utilize rookie center Greg Stiemsma if they desire more size).

Rivers told reporters in Oklahoma City Wednesday that, if O'Neal or Wilcox is sidelined for an extended period, the team might have no choice but to seek another big body. Given that Boston is at the 15-man roster limit, the Celtics would have to facilitate a trade or release a player, eating that contract, in order to free space.

"It's pointing that way for sure," Rivers told reporters Wednesday at the team's shootaround, according to the Boston Globe. "But I think we'll find out more once Chris and JO get back [to Boston], but the way they've been injured so much, we may need to get one anyway. I think that's something that [Celtics president of basketball operations] Danny [Ainge] and I will talk over the All-Star Break. But listen, if there's a big out there, there's a reason he's out there. There's someone out there, we just don't know who it is yet."