Former Red Sox outfielder Marlon Byrd was suspended 50 games by Major League Baseball Monday for testing positive for Tamoxifen, a performance-enhancing drug.
Byrd defended himself in a statement released by the Players’ Association, claiming the positive test was caused by a medication he began taking during the winter that was needed for symptoms related to a surgery “private and unrelated to baseball’’ several years ago.
“I made an inexcusable mistake,’’ Byrd said. “Although that medication is on the banned list, I absolutely did not use it for performance-enhancement reasons.’’
Tamoxifen is commonly used to treat breast cancer in men and women, boosting testosterone levels. It also can help alleviate potential side effects caused by steroids.
Byrd, 34, was acquired from the Cubs in April and appeared in 34 games with the Sox, hitting .270 with one home run and seven RBIs. He was released June 12 and remains a free agent.
Team officials denied any knowledge of Byrd’s alleged use of a performance-enhancing substance.
“He played here and he played well,’’ manager Bobby Valentine said. “But I had no indication. I don’t think anybody here did.’’
When asked if Byrd had been tested with the Red Sox, Valentine was unsure.
“But I can tell you, I was just in the training room and they had no idea that he even got found out,’’ Valentine said.
Sox general manager Ben Cherington was equally at a loss when asked about Byrd’s suspension.
“I found out about it before everyone else did,’’ he said.
During spring training with the Cubs, Byrd acknowledged that he still maintained a relationship with Victor Conte, who pleaded guilty to steroid distribution in 2005 during the BALCO scandal and served four months in prison. In 2009, Byrd admitted using supplements provided by Conte that were not in violation of MLB’s drug prevention program.
Byrd said Conte had nothing to do with his positive test, and Conte wrote on his Twitter account after the suspension was announced that he “provided Marlon Byrd with nutritional and training advice which had nothing whatsoever to do with any type of prohibited substances.’’
“I am mortified by my carelessness and I apologize to everyone who loves this game as I do,’’ Byrd said. “I will serve my suspension, continue to work hard and hope that I am given an opportunity to help a club win later this season.’’Alex Prewitt can be reached at firstname.lastname@example.org. Follow him on Twitter @alex_prewitt. Nick Cafardo of the Globe staff contributed to this report.