Whitley was placed on the minor-league injured list Saturday with right elbow discomfort, Chandler Rome of The Athletic reports.
Whitley made his major-league debut with the Astros on April 16, allowing one hit and one walk but no runs over two-thirds of an inning against Atlanta. He was sent back to Triple-A Sugar Land after that outing, and he has thrown two scoreless innings while striking out four over his last two appearances in the minors.