Welington Castillo, catcher for the Chicago White Sox, has just been suspended without pay after testing positive for the performance-enhancing substance Erythropoietin (EPO). Using such substances is in violation of the Joint Drug Prevention and Treatment Program put in place by Major League Baseball.

Castillo, 31, issued a statement expressing his regret and apologies for what he called an “extremely poor decision.” In his statement, Castillo went on to say he is aware that he let many people down, including his family, teammates, the fans and the White Sox organization.

Erythropoietin (EPO) is a hormone naturally produced by the kidneys that promotes red blood cell formation. An increased number of red blood cells raises oxygen-carrying capacity in the blood and tissues, enhancing athletic performance. EPO is one of the substances cyclist Lance Armstrong was using during his doping scandal.

Welington Castillo is known as a reliable veteran who was hitting .267 at the time of the suspension. He has had six home runs and 15 RBIs thus far and has allowed the White Sox to develop other players more gradually. He came to the White Sox in a $15 million two year free-agent deal that also included an $8 million club option for the year 2020, a crucial part of the team’s rebuilding phase. Castillo has worked quite a bit with young pitchers Reynaldo Lopez, Carson Fulmer and Lucas Giolito as well as catchers Seby Zavala and Zack Collins.

The coaching staff and numerous teammates have applauded Castillo’s willingness to take responsibility for his actions and issue a heartfelt public apology. While the White Sox recently enjoyed an 11-1 victory, it was bittersweet for the team.

An 80-game suspension is an extremely high price to pay, and both Welington Castillo and his team will be feeling the effects for a good portion of the season. However, his teammates and management are confident he will come back better – and wiser – than ever before.