Houston Astros minor leaguer Forrest Whitley, one of the game's top pitching prospects, has been suspended 50 games for a violation of minor league baseball's drug program, Major League Baseball announced on Wednesday.

Whitley's suspension is without pay.

Whitley, 20, was the Astros' first-round pick in 2016 (17th overall). A product of Alamo Heights High School in San Antonio, Whitley advanced from low-A ball to Double-A last season.