"Manny Ramirez walked away from baseball today after testing positive for a performance-enhancing drug, abruptly ending the mercurial career of one of the most talented - and tainted - hitters to ever play the game.

The slumping Tampa Bay slugger informed Major League Baseball that he would retire rather than face a 100-game suspension. Ramirez served a 50-game ban for violating the drug policy in 2009, and second-time offenders get double that penalty.

"We were, obviously, surprised when we found out about it today, and hurt by what transpired," said Rays vice president Andrew Friedman, who signed Ramirez to a $2-million, one-year contract in the off-season. "We were cautiously optimistic that he would be able to be a force for us."

A person familiar with the situation confirmed to the Associated Press that the 12-time All-Star tested positive for a performance-enhancing drug. The person spoke on condition of anonymity because the nature of Ramirez's issue with MLB's drug policy was not publicly disclosed.

The commissioner's office announced Ramirez's decision in a statement but provided few details.

"Major League Baseball recently notified Manny Ramirez of an issue under Major League Baseball's Joint Drug Prevention and Treatment Program," the statement said. "Ramirez has informed MLB that he is retiring as an active player. If Ramirez seeks reinstatement in the future, the process under the Drug Program will be completed."

MLB said it would have no further comment."