Houston Astros starting pitcher Collin McHugh will be out an additional six weeks due to a right elbow injury.

McHugh, who started the season on the 10-day disabled list because of tendinitis in his right shoulder, left his rehab start with Triple-A Fresno this past Thursday with elbow discomfort. McHugh lasted one inning before being pulled from the game.

Astros team physicians in Houston on Friday diagnosed McHugh with posterior impingement of his elbow. An MRI revealed that the ulnar collateral ligament in his elbow was normal.

McHugh will not undergo surgery at this time and will be re-evaluated in six weeks.

The right-hander was 13-10 with a 4.34 ERA in 2016.