Matt Gelb and Bob Brookover of the Philadelphia Inquirer report that Ruiz had tested positive for the stimulant Adderall, a prescription medication used to treat Attention Deficit/Hyperactivity Disorder (ADHD).

An initial positive amphetamine test triggered the enhanced testing process, the Inquirer reports:

Under MLB's program, Ruiz was subject to six unannounced follow-up tests over the 12 months after the initial violation, in addition to the standard random testing. A first positive test for a stimulant, unlike steroids, does not result in suspension. Instead, the increased testing is implemented. Ruiz would be suspended for 80 games should a third positive test emerge.

Ruiz, through the Major League Baseball Players' Association, issued a statement:

I am sincerely regretful for my mistake in taking a prohibited stimulant.

I apologize to my teammates, the Phillies organization, and the

Philadelphia fans. I will serve the imposed 25-game suspension to begin

the season and I look forward to returning to the field and working toward

bringing a championship back to Philadelphia in 2013.