The Astros placed Walter on the 15-day injured list Friday, retroactive to July 24, due to left elbow inflammation.

EDGE Analysis

Walter threw seven innings in a start Wednesday, but his arm didn't recover as expected, and he'll require a stint on the injured list. Houston recalled reliever Nick Hernandez from Triple-A Sugar Land in a corresponding move, but it's unclear who will take Walters' spot in the rotation.