The last major leaguer to be suspended for a positive test was Ramirez, one of four players given 50-game penalties in 2009. Three major leaguers were suspended in 2008, 8 in 2007, 3 in 2006 and 12 in 2005. Those numbers are much lower than the most recent figures in the minor leagues, where 83 players were suspended last year, many of them teenagers in the Dominican Summer League hoping to graduate to the regular minor league system.

Volquez initially signed with the Texas Rangers when he was 18. He came up through their system and in December 2007 was traded to the Reds as part of the deal that sent Josh Hamilton to the Rangers. He had a breakout season in 2008 when he went 17-6 for the Reds. But hampered by various injuries, he started only nine games for the Reds in 2009, going 4-2.

Volquez said in the written statement that toward the end of last season, he and his wife sought medical advice in Cincinnati from a doctor about starting a family. That doctor, he said, provided him with prescriptions to treat a medical condition. Volquez then returned to the Dominican Republic. Volquez did not identify the prescriptions or the medical condition.

“As a follow-up to our original consultation, my wife and I visited another physician in our home city in the Dominican Republic this past off-season,” he said. “This physician also gave me certain prescribed medications as part of my treatment. Unfortunately, I now know that the medication the physician in the Dominican gave me is one that is often used to treat my condition, but is also a banned substance under Major League Baseball’s drug policy.”

Last May, baseball officials suspended Ramirez after they discovered he had used the substance human chorionic gonadotropin, or H.C.G. Doctors typically prescribe that substance to men who have low levels of testosterone or are experiencing fertility problems.

In a statement last May that was similar to Volquez’s, Ramirez said: “Recently, I saw a physician for a personal health issue. He gave me a medication, not a steroid, which he thought was O.K. to give me. Unfortunately, the medication was banned under our drug policy. Under the policy that mistake is now my responsibility.”

Volquez said in his statement that he tested positive in spring training, when all players are subject to at least one test. “I simply want to accept the consequences, learn from the mistake, and continue to strive to be the best person and baseball player I can be,” he said.