Prior to Thursday's series finale at Great American Ball Park, the Dodgers placed Weaver on the 15-day disabled list with a right lower back strain and reinstated left-hander Hong-Chih Kuo.
"They didn't want to push the issue this early in the season," Weaver said. "It just seemed logical [to go on the DL]. It's just a little joint compression. [Trainer] Stan [Conte] did some spinal maneuvers, ultrasound and applied heat today. It's tolerable."
Weaver suffered the injury while throwing a pitch to Ramon Hernandez in the eighth inning of Wednesday night's victory over the Reds.
"Weaver may not need the time," said Dodgers manager Joe Torre. "I don't want him to think it's only going to be three days and rush back. We think this is the safest thing to do."
Weaver's disabling ends a long wait for Kuo, who's missed 14 games with a sore left elbow. Torre said Kuo will be eased back into the bullpen.
"He'll go every other day for the foreseeable future -- not going back-to-back at this point," said Torre. "I trust him. He's been champing at the bit to get back."