OAKLAND, Calif. -- Make it two 50-game suspensions in exactly one week -- both starters for contending teams from the Bay Area, both for testosterone.

Former Cy Young Award winner Bartolo Colon of the Oakland Athletics was suspended for 50 games Wednesday after a positive test, joining San Francisco Giants outfielder Melky Cabrera on the suspended list for the rest of the regular season.

Major League Baseball made the announcement of Colon's penalty a week after All-Star Game MVP Cabrera received his 50-game suspension

"I apologize to the fans, to my teammates and to the Oakland A's," Colon said in a statement released by the players' association. "I accept responsibility for my actions and I will serve my suspension as required by the joint drug program."

He will miss the final 40 games of the regular season and the first 10 games of the postseason if Oakland advances that far. Any remainder of the suspension would be served in a future season, if Colon signs another major league contract.

"It's a shock," Oakland reliever Grant Balfour said. "He's a guy that we're definitely relying on right now. I guess you could say it's bad timing any time, but especially now."

Oakland, which hasn't made the playoffs since 2006, began Wednesday a half-game out in the AL wild-card race. The A's were preparing for an afternoon series finale against Minnesota when they got the news from clubhouse televisions. A closed-door team meeting was called.

"The Oakland Athletics are disappointed to learn of today's suspension," the team said in a statement.

Starter Brandon McCarthy took that a little further.

"You can say someone's a good teammate, but it has to extend in all facets," McCarthy said after a 5-1 win. "Off the field, on the field and how you are in the clubhouse, no matter how look at it, we've now lost a really important part of our team to his actions."

General manager Billy Beane received word from MLB earlier Wednesday and began searching for a starter to take Colon's turn in the rotation Thursday at Tampa Bay. Tyson Ross will be called up from Triple-A Sacramento. Ross arrived to the Coliseum and moved into Colon's locker.

"It shocked all of us just the fact someone got caught for that," Ross said.

Beane addressed the A's in the clubhouse before the team took the field for pregame warmups.

"Listen, it's disappointing. From a baseball standpoint, we're scrambling," Beane said. "We're all disappointed, not just for the Giants and the A's, but for baseball."

The 39-year-old Colon is 10-9 with a 3.43 ERA in 24 starts this season, his first with the A's, and has a 171-122 record in 15 big league seasons. A two-time All-Star, the burly right-hander won the 2005 AL Cy Young Award after going 21-8 for the Los Angeles Angels.