Astros top pitching prospect Forrest Whitley has been diagnosed with a sprain of the ulnar collateral ligament in his right elbow, the club announced on Sunday. Whitley is seeking a second opinion before he finalizes his plans for treatment, but a UCL sprain typically requires Tommy John surgery.

Whitley, 23, began experiencing discomfort in his elbow while throwing live batting practice last week at Astros camp in West Palm Beach, Fla. The No. 41-ranked prospect in baseball by MLB Pipeline, Whitley hasn’t appeared in a Grapefruit League game this year.

The injury is the latest setback for the 2016 first-round pick, who was added to the 40-man roster this year and came to camp looking to establish himself after a series of setbacks the last few years.

In 2019, Whitley posted a 7.99 ERA in four Minor League levels, including 12.21 at Triple-A Round Rock before being placed on the injured list with shoulder fatigue. In 2018, he was suspended 50 games for a violation of the Minor League drug prevention and treatment program and sustained two oblique injuries. He appeared in only 23 games across three levels, posting a 2.92 ERA with 143 strikeouts in 92 1/3 innings.

If Whitley decides to undergo Tommy John surgery, he wouldn’t pitch again until 2022. That would make it two consecutive seasons without game action after the Minor League season was canceled last year. Whitley worked out last summer at the team’s alternate training site.