Cobb was placed on the 10-day injured list with a lumbar strain.
This is a lower-back injury and it's the first we've heard of Cobb dealing with the injury. He was supposed to start Wednesday against the A's. Rich Dubroff of BaltimoreBaseball.com noted that it could be Josh Rogers or Yefry Ramirez who gets the call from Triple-A to make that start. The move is retroactive to April 6.