The chances are slim. OK, very slim.

But the Tampa Bay Rays host Oakland in a weekend series beginning Friday with their last chance at making a run at the Athletics for an American League wild-card spot.

This is a three-game series between the two hottest teams in the league, but an Oakland loss in Baltimore on Thursday night left the idle Rays eight games behind the A's, who trail the idle New York Yankees for the top wild-card position by 1 1/2 games. The A's also fell 3 1/2 games behind the Houston Astros atop the AL West.

Obviously, the only chance Tampa Bay might have hinges on a sweep this weekend and while the Rays have won 18 of their last 22 games overall and 13 of their last 14 at home, the chance of Oakland losing all three games seems remote at best.

Even with Thursday night's loss, which ended a six-game winning streak, the A's are 55-22 in their last 77 games. Before the loss, they were 32 games over .500 for the first time since Sept. 23, 2003.

They have a magic number to clinch the wild-card spot of nine, but face a hot Tampa team that has built a strong belief in itself down the stretch.

"You hope that we're learning a lot about ourselves right now," Rays manager Kevin Cash said Wednesday. "Bring some excitement to the rest of this year and going into the offseason. Getting to watch this from a really good seat, it's pretty exciting. I hope it's exciting for our fans. Because these guys, they come every day, they bring a lot of effort, they're fun to watch and they're very talented."

Veteran Edwin Jackson, who is 5-3 with a 3.26 ERA this season since joining the A's (his 13th team), works the first game of the series on Friday, while Cash goes with "opener" Diego Castillo (3-2, 3.45 ERA), with 14-game winner rookie Ryan Yarbrough slated to do the bulk of the work.

Jackson is 1-1 in his last five starts and is coming off a rough outings against the Rangers in Oakland, giving up four runs on five hits, including two home runs, in three innings of a no-decision. The A's won the game 8-6.

Yarbrough is 14-5 with a 3.78 ERA and will take over for Castillo, who gave up a run in two innings as the "opener" Monday night. Yarbrough had a 5 2/3-inning relief appearance with nine strikeouts while allowing three runs May 31 against the A's as the Rays won three of four at Oakland, which is 20-9 versus the AL East.

Both teams come in with former Cardinals in the midst of hitting streaks -- Tampa Bay's Tommy Pham with a 16-game streak and Oakland's Stephen Piscotty a 14-game streak after hitting a home run in Baltimore Thursday night.

The A's, who has lost ace Sean Manaea for the season with shoulder surgery, announced Trevor Cahill, who was scheduled to start Saturday's game, had gone home for an MRI on a strained rhomboid muscle in his back. The hope is he'll be able to start twice on Oakland's final homestand of the season.

"Hopefully it's just a muscular thing," Oakland manager Bob Melvin said before Thursday's game. "Felt it last time out, so we're going to send him back. He's had some trouble in certain areas before, so we want to make sure we cover our bases. Hopefully we know a little bit more tomorrow about what the results are, and hopefully it's only one turn around."

Tampa's Matt Duffy missed the last three games with back stiffness but was available to pinch hit Wednesday and hopes to play Friday night.