Eddie Rosario, one of the Twins’ top prospects, was suspended for the first 50 games of the 2014 season after failing a drug test for the second time, Major League Baseball announced Saturday.

Rosario, an outfielder and second baseman, failed a test for a “drug of abuse,” the commissioner’s office said, mandating a 50-game penalty under the sport’s Minor League Drug Prevention and Treatment Program. News of his potential suspension leaked in November but was not confirmed by MLB at the time.

“It’s disappointing, but now he has to pay the consequences and be accountable,” General Manager Terry Ryan said. “Losing 50 games, that’s a huge setback. That’s a lot of development time, a lot of learning that he’ll miss. It sets back his progression [toward] going up to the big leagues. But young people make mistakes, and hopefully he learns from it.”

Rosario apologized in a statement released by his agent. “I made a mistake and I have no one but myself to blame,” he said.

The native of Puerto Rico, a fourth-round draft pick in 2010, batted .329 in 52 games with Class A Fort Myers last season before being promoted to Class AA New Britain, where he hit .284 with seven home runs in 70 games. The Twins thought so much of Rosario’s potential they included him among the seven prospects they sent in October to the Arizona Fall League, where he batted .238 in 20 games against advanced competition.

Now Rosario, 22, will come to spring training in March as scheduled, and he will take part in drills and exhibition games. But once the season begins, Rosario likely will remain behind in Fort Myers, Ryan said.

“We’ll keep him under our eye, whether it’s at spring camp or somewhere else,” Ryan said. “That’s a sizable part of the season, but that’s the price you pay for not being responsible enough to understand right from wrong.”

Rosario must wait until the team he is assigned to plays 50 games in 2014 — if it’s New Britain again, Rosario would be eligible to return May 25 (or later if there are rainouts) — and will be required to undergo additional drug testing during the season. A third positive test would result in a 100-game suspension. The suspension is for an undisclosed “drug of abuse,” such as marijuana or cocaine, as distinct from a performance-enhancing drug, which brings a 100-game suspension for a first offense.

Rosario is the second Twins minor leaguer to be suspended for failing a drug test in recent months. In September, Class A Cedar Rapids pitcher Dallas Gallant received a 50-game suspension for an amphetamine test.