The move came a day after Lerew surrendered three earned runs and five hits in two innings of a 13-3 loss at Boston and departed after complaining of an ailing right elbow.
"I've had a little soreness in my elbow for the last month or so," Lerew said on the team's Web site. He was making his third start since being brought up to Atlanta on May 8.
"It's kind of affecting the way I'm releasing the ball right now. I've just got to get some treatment on it and figure out what's going on."
In three starts, Lerew is 0-2 with a 7.71 ERA in 11 2/3 innings.
Manager Bobby Cox had to use five relievers in his place.
Atlanta rebounded in Saturday's nightcap. Veteran John Smoltz allowed only three hits in seven scoreless innings in a 14-0 victory.