The Los Angeles Dodgers star said he did not take steroids and was prescribed medication by a doctor that contained a banned substance. The commissioner's office didn't announce the specific violation by the 36-year-old outfielder, who apologized to the Dodgers and fans for "this whole situation."
"Recently I saw a physician for a personal health issue. He gave me a medication, not a steroid, which he thought was OK to give me," Ramirez said in a statement issued by the players' union.
"Unfortunately, the medication was banned under our drug policy. Under the policy that mistake is now my responsibility. I have been advised not to say anything more for now. I do want to say one other thing; I've taken and passed about 15 drug tests over the past five seasons."
The suspension began Thursday and barring any postponements Ramirez will be able to return to the Dodgers - who now have the best record in baseball - for the July 3 game at San Diego. Ramirez will lose about $7.65 million of his $25 million salary.
While Barry Bonds, Roger Clemens, Alex Rodriguez, Jose Canseco and a long list of stars have been implicated in the use of performance-enhancing drugs, Ramirez is the most prominent suspended under the drug policy players and owners put in place seven years ago.
"I think a lot of people are just stunned that a name like Ramirez [is] getting gathered up in this net Major League Baseball has put out," sports reporter Randy Kerdoon told CBS News. "He's been, with a few exceptions and a few 'Manny moments,' pretty much a model citizen since coming [to the Dodgers] from the Red Sox last year."
But, "The truth of the matter is, he did by his own admission take a performance enhancing drug," Tom Verducci of Sports Illustrated told CBS News chief investigative correspondent Armen Keteyian.
Over the years Ramirez's hair-raising antics - like being spotted in a bar after claiming he was too sick to play and refusing to pinch hit in a game - prompted their own catch-phrase: "Manny being Manny," Keteyian reports.
The report of Ramirez's failed drug test and impending suspension was first reported in the Los Angeles Times Thursday.
The league formally issued the suspension soon after the report became public.
Earlier this year, New York Yankees star Alex Rodriguez admitted taking steroids between 2001 and 2003 after a Sports Illustrated report detailed a failed drug test in 2003. Rodriguez wasn't suspended because the failed test predated the league's formal drug policy.
The players' association said Ramirez was suspended by the commissioner under the "just cause" provision of section 8.G.2 of the joint drug agreement. That allows players to be penalized for use, sale or distribution of banned substances, even where the agreement doesn't specify a particular penalty, such as for a positive test.
In his statement, Ramirez addressed Dodgers owners Frank and Jamie McCourt, and manager Joe Torre.
"I want to apologize to Mr. McCourt, Mrs. McCourt, Mr. Torre, my teammates, the Dodger organization, and to the Dodger fans," Ramirez said. "LA is a special place to me, and I know everybody is disappointed. So am I. I'm sorry about this whole situation."
Ramirez is the third player suspended this year under the major league program, following Philadelphia reliever J.C. Romero and Yankees pitcher Sergio Mitre.
Just two relatively low-profile players were suspended under the major league program last year, San Francisco catcher Elizier Alfonzo and Colorado catcher Humberto Coto.
In the past, the best-known player penalized was Baltimore's Rafael Palmeiro, who received a 10-day suspension in 2005, the first year of penalties for first infractions.
Ramirez was acquired by Los Angeles from Boston last July 31 and became a fan favorite. His contract negotiations became a long-running drama during the offseason, and he agreed in early March - well after the start of spring training - to a $45 million, two-year contract that gives him the right to void the second season and become a free agent again.
Los Angeles even renamed a section of seats in left field at Dodger Stadium "Mannywood" in his honor.