According to Jon Heyman of CBS Sports, Oakland Athletics starting pitcher Bartolo Colon faces a 50-game suspension for failing an MLB drug test by testing positive for testosterone.

Colon missed all of 2000, but bounced back last season with the New York Yankees after receiving a controversial stem-cell treatment on his arm that is typically coupled with the use of human growth hormone. The right-handed pitcher denied that he underwent that aspect of the treatment at the time, and this past off season he doubled his salary from the previous year, and signed a $2 million deal with Oakland.

This season, Colon has made 24 starts with the A’s, and ranks as the team’s second best starter according to fWAR. It’s a blow for the Athletics who surprisingly find themselves in playoff contention, currently a half game back of a Wild Card spot. However, Brett Anderson’s recent return from injury and Dan Straily’s effectiveness should mitigate some of the loss from Colon’s departure.