The fallout of Bartolo Colon's suspension begins Thursday night for the Oakland Athletics, who turn to Tyson Ross to fill the void in the opener of an odd three-game series with the Tampa Bay Rays.

Colon was slated to pitch this opener, but was banned for 50 games on Wednesday after testing positive for testosterone, violating the league's drug policy.

It was the second suspension of its kind in a week after San Francisco Giants All-Star outfielder Melky Cabrera was hit with a 50-game penalty for also testing positive for testosterone.

The 39-year-old Colon went 10-9 with a 3.43 earned run average in 24 starts this year, but the former AL Cy Young Award winner won't pitch again this regular season. Oakland has 40 games left, but does currently own a half-game edge for the second wild card spot in the league. Colon's suspension would carry over into the postseason should the Athletics qualify.

"I apologize to the fans, to my teammates and to the Oakland A's," said Colon in a statement through the MLB players union. "I accept responsibility for my actions and I will serve my suspension as required by the Joint Drug Program."

The A's will recall Ross from Triple-A Sacramento, where he has gone 5-2 with a 2.74 ERA this season. He is 2-8 with a 6.35 ERA in 12 starts with Oakland this season, but hasn't pitched in the majors since June 28.

The right-hander headed to the minors having lost five straight decisions, not winning since May 14.

Ross faced the Rays for the first time as a starter on May 4 and was drilled for seven runs on nine hits and two walks in a loss.

The 25-year-old does think his time in the minors has helped.

"I've been in Sacramento the past 2 1/2 months getting a chance to work a few things out," Ross said on Oakland's official website. "I feel like I've gone in the right direction."

The A's have been doing that by winning six of their past seven games. In addition to holding a wild card spot, they are five games back of the first- place Texas Rangers in the AL West.

Tommy Milone snapped a four-start losing streak in a 5-1 win over the Minnesota Twins on Wednesday, allowing a run, two hits and a walk in eight innings of work.

Coco Crisp picked up three hits, including a home run, drove in a pair of runs and scored three times for Oakland.

The Rays are the other current wild-card team and picked up their sixth victory in seven games on Wednesday, downing the Kansas City Royals 5-3.

James Shields won his fourth straight decision, fanning 34 with a 2.15 ERA over that span after he gave up three runs over 7 2/3 innings.

"I was mixing my pitches pretty well," Shields said. "Overall I kept them off balance."

Jose Lobaton hit a solo homer and B.J. Upton tallied two hits for the Rays, who trail the New York Yankees by three games for first place in the AL East.

Alex Cobb gets the start for Tampa Bay looking to extend his unbeaten streak to five straight starts. The right-hander began that stretch by beating the A's on Aug. 1, holding them to a run over seven innings.

Cobb would post two more seven-inning victories, allowing a run in each, before getting drilled by the Los Angeles of Anaheim on Saturday. He yielded eight runs and 12 hits over just 2 2/3 innings, but did not get a decision in his team's 10-8 win.

The 24-year-old is 7-8 and his ERA jumped to 4.74 through 16 starts. He is 1-1 with a 4.74 ERA in two career starts against Oakland.

This series will actually wrap on Saturday due to the Rays' Tropicana Field being used for the Republican National Convention party on Sunday.

Oakland and Tampa Bay have split six meetings so far this season.