"Sadly, the comments made by Mr. Mejia and his representatives [Friday] continue a pattern of athletes hiring aggressive lawyers and making wild, unsupported allegations about the conduct of others in an effort to clear their names.
"Mr. Mejia's record demonstrates that he was a repeated user of banned, performance-enhancing substances. As such, per our collectively bargained rules, he has no place as an active player in the game today."
After his third positive test triggered a lifetime suspension, Mejia told the The New York Times that he was being punished because he declined to share information about his doping connections after his first failed test.
Mejia was suspended twice in 2015 for using anabolic steroids and was permanently barred from baseball in February.
The pitcher upped the ante Friday with the announcement that he plans to appeal his ban.
His lawyer, Vincent White, told reporters that his client "feels he has no choice but to fight," and claimed he had spoken to several witnesses, one of whom accused MLB of hacking into player's online accounts.
Said Mejia at a press conference Friday: "I'm here to appeal the case because I don't feel guilty and I feel like something has come over me. I understand that I'm not guilty for something that I have been accused."
Mejia, who hinted that he believes he's being targeted because he's a Latino, said he had offers to continue his career in Korea.
"I'm a person with dignity and I know that I can clean my name fighting my case, but I can't clean my name dirtying another name. I'm just a ballplayer who wants to be real," Mejia said.
"The first test came positive and I admit it in front of the cameras and in front of the world. I was sick and I found something that my brother was using and I used it. I admitted in that time. [Now] I'm here to appeal my case. I'm not here to lie and talk about someone else. I'm a person with values and feelings. I'm here looking for support because I feel that my career could end at any moment."
Paul Hagen is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.