Howard was hurt Aug. 1 sliding back into second base at Washington. He was activated before Saturday's game against the Nationals.
Howard played one rehab game on Friday night. He's batting .292 with 23 homers and 81 RBIs.
To make room for Howard, outfielder Ross Gload was placed on the DL. Gload strained his groin on Aug. 11 against the Dodgers after hitting a double in the sixth inning.