Rollins missed 29 games with a strained right calf before rejoining the lineup Monday. He returned to his customary leadoff spot Friday, but left in the sixth inning after feeling a pop while running to first base on a single.
An MRI exam Saturday revealed a strain, according to Philadelphia general manager Ruben Amaro.
In 12 games, the speedy Rollins is batting .341 with two homers and seven RBIs. He is eligible to come off the disabled list on June 6.
"There's no sense in playing around with it. ... His legs have to be well," Phillies manager Charlie Manuel said. "He has to be 100 percent. We can't be knocked around waiting for him to play, on and off. He has to get 100 percent."