Preview: Chen looks to cool Orioles' hot bats

The Baltimore Orioles' only defeat during their latest surge came in Jason Hammel's most recent start, which isn't much of a surprise given his nearly two-month winless stretch.

Hammel looks to begin his second half on a high note as visiting Baltimore tries to extend its season-best winning streak to six against the slumping Kansas City Royals on Tuesday night.

The Orioles (57-43) have been on a tear of late, beating the Royals 9-2 in Monday's series opener for their eighth victory in nine tries. J.J. Hardy hit a two-run homer and Chris Davis, who leads the majors with 97 RBIs, added a two-run double as each drove in three runs.

Seven players had multi-hit games as Baltimore matched its season high with 18 hits.

"The way we're swinging the bats, we know that if one guy doesn't do it, the next will do it," Davis said.

Baltimore's last defeat came July 13, when Hammel allowed six runs and 10 hits over six innings of a 7-3 loss to Toronto.

Hammel (7-6, 5.24 ERA) hasn't won since beating Washington on May 27, going 0-4 with a 5.59 ERA over his past eight starts -- seven of which have been Orioles losses.

He surrendered another homer in his most recent outing, pushing his total to 19 after allowing nine in 20 starts last season.

"I am not throwing sliders for strikes. Not throwing curveballs where I want them. Changeup is non-existent. I'm beating myself right now," Hammel said. "I'm better than this. And it's on my shoulders. It's on nobody else's. It's fixable."

Manager Buck Showalter is confident the right-hander can get back on track.

"He's pitched some good games," Showalter said. "I think it bodes well for the rest of the season because he's capable of better and I think his best games are ahead of him."

Hammel had gone 0-2 with a 7.63 ERA in three starts versus the Royals while in the NL before striking out seven in six scoreless innings of an 8-2 win May 25, 2012. He'll seek a similar effort against a Kansas City team that has dropped seven of nine after Monday's loss.

The Royals (45-51) have averaged only 2.4 runs during their slump. They'll look to improve on that production for Bruce Chen, who will be making his second start after 19 relief appearances.

Chen (3-0, 2.04) replaced the struggling Luis Mendoza in the rotation before the All-Star break and allowed one hit and struck out four over six innings July 12, but the Royals fell to Cleveland 3-0.

"I'm very happy with the way I pitched," said Chen, who went 11-14 with a 5.07 ERA in 34 starts last season. "I did everything I could to help us win."

Manager Ned Yost acknowledged Chen likely could have remained in the game, but the left-hander hadn't pitched more than 4 2/3 innings prior to that outing.

"Bruce really threw the ball well for us," Yost said. "I suppose he could have gone longer, but realistically, he had done his job. He threw six strong innings."

Chen, who spent 2004-06 with Baltimore, pitched two scoreless innings against his former team in Kansas City's 5-3 loss May 8.

He's 2-3 with a 5.52 ERA in six career starts versus the Orioles. Nick Markakis, who had three hits in Monday's opener, is 8 for 16 with three doubles and a homer against Chen.