Perez was suspended for 80 games Friday after testing positive for a third time for a banned stimulant, a penalty that finishes his season and might also end his 12-year career.
"It's not fair," said Perez in a conversation with ESPNdeportes.com from his home in Detroit.
"They called three different positives on a 20-day-period. I was using a medicine that was supposedly authorized by the doctors due to a personal condition."
Perez was suspended for 25 games on July 6 when he tested positive for a second time and was set to return on Saturday. Under baseball's labor contract, a player who tests positive for the first time is sent for counseling.
He will miss the final 54 games of the regular season and finish serving the suspension next year, if he is signed. Because of his initial positive test, Perez is subject to at least six additional tests over the next year.
"Many people might be trying to understand how is it possible that a player tests positive for the same substance three times in half a season," Perez said. "The truth is that they tested me four times between May 10th and June 1st and they never told me if there was anything wrong. I have been using that same medicine all this time."
Perez said that by the end of last season, he could not focus on games and visited a psychologist, who diagnosed him with ADHD and prescribed him Adderall, an amphetamine.
Perez claims that the team gave him the medicine and he used it at the end of last season, including during Detroit's playoffs and World Series run. But when spring training began, Perez finished his dose and the doctors gave him a new prescription.
"I went to two different drug stores and they wouldn't sell me the medicine, so someone from the team told me I could use any amphetamine and I started using something else," said Perez. "They tested me during spring training and everything was negative. But then in May I guess I tested positive, but they never told me there was something wrong.
"Even twice, they only tested me, when the regular procedure is to test at least four or five players."
Perez said that the MLB Players Association appealed the last suspension, but could not change the decision.
His initial suspension cost him $396,175, and the second will cost him $792,350 -- a total of $1,188,525 of his $2.5 million salary.
"I can't care less about the money. I'm worried about my family's honor," Perez said.
The 34-year-old Perez, who is hitting .172 with one homer and six RBIs in 64 at-bats for the defending AL champions, said he hopes to find a new job for next year, although he knows it won't be an easy task.
"My conscience is clear", said Perez, who owns a .267 batting average in 12 seasons.
Perez won a Gold Glove at shortstop in 2000 with Colorado and also has played for Kansas City, San Francisco and the Cubs.
Enrique Rojas is a reporter and columnist for ESPNdeportes.com and ESPN.com.