Cardinals’ minor-league pitcher Corey Littrell was suspended for 50 games by Major League Baseball on Wednesday for a second positive test for “a drug of abuse.”

A press release from Major League Baseball announcing the suspension of Littrell and four other minor-leaguers from other organizations did not offer any more specific details.

Littrell was a non-roster invitee to the Cardinals’ major-league camp, where workouts began on Tuesday, but he had not appeared in camp.

A 24-year-old lefthander, Littrell pitched at Springfield and Memphis last season. He appeared in a combined 53 games, 52 of them in relief, and had a 2-4 record.

The Cardinals acquired Littrell in a trade with the Boston Red Sox in 2014 which also brought John Lackey to the Cardinals in exchange for Allen Craig and Joe Kelly.