(Sports Network) - The Baltimore Orioles continue a lengthy road trip tonight with the first of three consecutive meetings with the Oakland Athletics from McAfee Coliseum.

Baltimore began its 10-game trek by losing two of three matchups to the American League West-leading Los Angeles Angels of Anaheim over the weekend. The Halos took Sunday's rubber match by a 6-5 score, with Gary Matthews Jr., Torii Hunter and Robb Quinlan all belting home runs off Orioles starter Steve Trachsel en route to the win.

Trachsel (1-4) lasted just three innings and was rocked for six runs on seven hits for Baltimore, which suffered its fourth loss in its last five games.

Melvin Mora paced the Orioles offensively with three hits, including a solo home run. Nick Markakis also homered in a losing cause, while Kevin Millar finished 2-for-4 with a pair of RBI for Baltimore.

Oakland also enters this series in a bit of a tailspin, as the club lost four times in a five-game stretch before Sunday's 3-1 victory over Texas. The Athletics scored three times in the bottom of the seventh inning and went ahead to stay on a two-run homer off the bat of Jack Cust.

Ryan Sweeney added an RBI single later in the frame and Frank Thomas ended 2- for-3 to help Oakland salvage the finale of a three-game set with the Rangers.

Santiago Casilla picked up the win with a shutout inning in relief of Greg Smith, who held Texas to one run and struck out a career-high 10 through the first six frames. Huston Street worked a scoreless ninth to notch his ninth save of the year.

Cust, a one-time Oriole, has homered in three of Oakland's last four contests and is batting .458 (11-for-24) during a current seven-game hitting streak.

Tonight's series opener will pit a pair of 24-year-old left-handers against one another, with Dana Eveland getting the assignment for the A's and Garrett Olson set to go for Baltimore.

Eveland, one of six players obtained by Oakland in the offseason trade that sent All-Star pitcher Dan Haren to the Arizona Diamondbacks, has compiled an impressive 3-2 record and a 3.67 earned run average through his first six starts with his new club. He's coming off his worst performance of the year, however, as Eveland surrendered season highs of six runs and seven hits in just 5 1/3 innings to lose to the Angels on Wednesday.

The southpaw, who will be facing the Orioles for the first time, has shined in a pair of starts at McAfee Coliseum this season. In those outings, Eveland yielded just two runs and fanned 10 over a combined 12 2/3 innings to defeat both Cleveland and Kansas City.

Olson was recalled from Triple-A Norfolk last week to replace the injured Adam Loewen in the Baltimore rotation and came through with an excellent performance to beat Tampa Bay on Tuesday. The young hurler took a shutout into the seventh inning against the Rays and permitted just two runs and four hits before exiting after 6 2/3 frames. He also matched a career best with six strikeouts.

A native of Fresno, California, Olson has never pitched against Oakland during his brief tenure in the majors. He made seven starts for the Orioles last season and posted a 1-3 record with a 7.79 ERA over 32 1/3 innings.

The A's and Orioles split eight 2007 encounters, with Baltimore winning twice during a three-game series at McAfee Coliseum last July. The O's are 6-3 in Oakland since the start of the 2005 season.