San Diego Padres outfielder Cameron Maybin has been suspended for 25 games for violating Major League Baseball's joint drug prevention and treatment program, the league announced Wednesday.

Maybin, whose suspension is effective immediately, tested positive for an amphetamine, the commissioner of baseball's office said in a statement.

The 27-year-old, who is the first player in the majors to be suspended this season for violating the drug program, said that his positive test came from a change in medication he had used to treat attention deficit disorder.

"Unfortunately, in my attempts to switch back to a medicine that had been previously OK'd, I neglected to follow all the rules and as a result I tested positive," Maybin said in a statement released by the MLB Players Association.

"I want to assure everyone that this was a genuine effort to treat my condition and I was not trying in any way to gain an advantage in my baseball career.

"I understand that I must accept responsibility for this mistake and I will take my punishment and will not challenge my suspension. I apologize to my family, friends, fans, teammates, and the entire Padres organization."

Maybin is batting .247 for the Padres this season with one homer and nine RBIs in 62 games.