Zimmerman, who was signed as a free agent from Washington, is 9-4 with a 3.95 ERA in 15 starts this season. He was the AL Pitcher of the Month in April after winning his first five starts. He is 4-4 in 10 starts since.
The second move to the DL is retroactive to July 1st, a day after Zimmerman took a no-decision in Tampa Bay against the Rays. He allowed four runs over six innings in that one.
The top-of-the-rotation hurler signed a five-year, $110 million contract with the Tigers after going 70-50 in six seasons with the Nationals. The two-time National League All-Star will be replaced in the rotation by Anibal Sanchez, who was recently moved to the bullpen.