AUBURN HILLS, Mich. -- The Detroit Pistons activated center Zeljko Rebraca on Tuesday, a day after they learned All-Star Ben Wallace will miss two weeks with a knee injury.

The Pistons also placed Danny Manning on the injured list because of a lower back strain.

Rebraca has been on the injured list since Jan. 6 because of an irregular heartbeat. The 7-footer from Yugoslavia was to be in uniform for Tuesday night's game at Philadelphia.

Rebraca, who turns 31 Wednesday, left a Dec. 21 game against New Jersey because of an accelerated pulse. He has averaged 6.3 points, 2.9 rebounds and 16 minutes in 26 games this season. He has missed 50 games.

Wallace, who leads the NBA in rebounding and blocks, could miss the start of the playoffs because of his injured left knee.