Kansas City at Baltimore

A young and talented roster is looking to lead the Baltimore Orioles to their first playoff appearance since 1997, when the latest addition to the team was only 5 years old.

Manny Machado, Baltimore's top prospect, is expected to make his major league debut Thursday night when the Orioles go for a season-high sixth straight win in the opener of a four-game series against the Kansas City Royals.

The third overall selection in the 2010 draft behind Bryce Harper and Jameson Taillon, the 20-year-old Machado has been playing with Double-A Bowie this season.

He's batting .266 with 11 homers and 59 RBIs in 109 games, mostly at shortstop, but the Orioles figure to use him at third base in the midst of their unlikely postseason push.

"The guy's got a lot of talent, and we feel like he can help," executive vice president of baseball operations Dan Duquette told the Orioles' official website. "Manny should be a plus defender, wherever we play him. He's a five-tool player, and he can help our team."

Another youngster came up big Wednesday as Steve Johnson went six innings and struck out nine to win his first major league start. Baltimore (60-51) beat Seattle 9-2 for its fifth straight win overall, matching the club's longest run of the season.

Nick Markakis went 8 for 16 with two homers and five RBIs in the three-game sweep of the Mariners, while Matt Wieters drove in five runs Wednesday alone after homering twice Tuesday.

Johnson's strong outing was the fourth time during the win streak that a Baltimore starter went at least six innings while giving up two runs or fewer.

Wei-Yin Chen (10-6, 3.46 ERA) is a good candidate to extend that success after giving up five hits - all singles - in seven innings of a 4-0 win Saturday at Tampa Bay.

The rookie left-hander is 3-1 with a 1.95 ERA in five starts since the All-Star break. He hasn't allowed an earned run over his last two outings, striking out 16 in 12 2-3 innings.

"He's got a good understanding of what's going on up here at this level right now, and we hope to ride it," manager Buck Showalter said.

Chen didn't receive a decision against the Royals on May 26 despite a sharp performance. He gave up two runs in six innings of Baltimore's 4-3 home loss.

Kansas City (47-63) took two of three in that series and did the same while visiting the first-place Chicago White Sox this week. Wednesday's 2-1 victory was the Royals' sixth win in nine games overall.

Following strong pitching performances by Bruce Chen and Jeremy Guthrie the last two days, the Royals will hand the ball to rookie Will Smith (2-4, 6.00), who makes his first appearance against the Orioles.

The left-hander is 2-0 with a 2.84 ERA in his last three road starts, but he gave up four runs and eight hits while walking three in 5 2-3 innings of a 4-2 home loss to Texas on Saturday.

"I feel a little step-by-step process," Smith told the Royals' official website. "Each day I go with a little something to work on out there and it just keeps coming."

The homers keep coming for Kansas City's Billy Butler, who went deep twice earlier this season in Baltimore - once off Wei-Yin Chen - and hit two more homers this week in Chicago to give him a career-high 22. Butler is 8 for 19 against the Orioles this year.