Top Houston Astros pitching prospect Forrest Whitley has been suspended 50 games without pay for a violation of the Minor League Drug Prevention and Treatment Program, Major League Baseball announced on Wednesday.

A native of San Antonio, Whitley was drafted with the 17th overall pick in the 2016 MLB Amateur Draft.

Baseball America ranks the 20-year-old right-hander as the No. 1 prospect in the Astros' system and the 10th-best in the MLB.

Whitley was expected to begin the year with the club's Double-A affiliate in the Texas League, the Corpus Christi Hooks.

In his first full pro season last year, Whitley worked his way through Low-A ball to High-A ball and finished the year with the Hooks.

Whitley posted a combined 5-4 record with an earned run average of 2.83 and a 1.213 WHIP over 92.1 innings pitched. He started 18 of the 23 games in which he appeared.

ESPN's Buster Olney was first with the news.