Oakland (63-77) was swept by Kansas City in a three-game series for the second time this season, losing a doubleheader against the AL Central's worst team Thursday to run its losing streak to four games.

Despite the A's troubles this season, they have a respectable 3.91 team ERA. But Oakland has posted a 6.55 ERA during its losing streak, with the light-hitting Royals batting .320 against it.

Baltimore's troubles, meanwhile, have lasted much longer. The Orioles are coming off an 0-6 road trip and have lost 13 of their last 15.

"It just wasn't a good road trip," Baltimore third baseman Aubrey Huff said. "We didn't even win a game on the whole road trip. We knew it would be a tough road trip ... we've got a lot of young guys up here learning on the job and there's going to be a lot of lumps."

Baltimore, though, has faced some tough teams over its last 15 contests, including six meetings with Boston, three with AL East-leading Tampa Bay, three with the AL Central-leading Chicago White Sox and three with the New York Yankees.

Playing without Melvin Mora, the Orioles managed to stay close in the finale of a three-game set against Daisuke Matsuzaka and the Red Sox, losing 5-4 on Wednesday.

Mora, selected August's AL player of the month on Wednesday, missed his fifth straight game due to a strained left hamstring and won't be able to play this weekend, according to the Orioles' official Web site.

"It's hard," he said. "You just want to be there, no matter what. Good or bad situation, you want to be there to help."

Huff, used primarily as a designated hitter, has been filling in for Mora at third base.

Huff and the Orioles will now face Dallas Braden (4-3, 3.88 ERA), who is 3-3 with a 3.59 ERA in eight starts since being moved into Oakland's rotation. The left-hander gave up two runs - one earned - and seven hits in six innings as Oakland beat Minnesota 3-2 on Saturday night.

Braden is 2-1 with a 1.17 ERA in two starts and one relief appearance against Baltimore.

In Thursday's doubleheader, A's starters gave up 12 runs in 9 1-3 innings. Oakland lost the opener 5-4 in 10 innings before dropping the nightcap 9-6.

The A's left a total of 19 runners on base. Now they'll face Orioles rookie Chris Waters (2-1, 5.45) for the first time. He is 1-1 with a 7.31 ERA in three starts at home, and 1-1 with a 6.61 ERA in his last three outings overall.

The left-hander allowed five runs and eight hits in 4 1-3 innings as Baltimore lost 10-9 to Tampa Bay on Saturday.

He'll try to help Baltimore win its first game in four meetings with Oakland this season.