Rasner was named the Yankees' fifth starter in the closing days of camp, when front-runner Jeff Karstens was placed on the disabled list with tendinitis in his right elbow. Rasner said that he developed a blister on the index finger of his pitching hand in the second inning, which affected the quality of his breaking pitches.
Making his first appearance of the season, the 26-year-old worked 4 1/3 innings, allowing eight hits and two home runs.
"Both of my offspeed pitches come off of that, but I'm not going to make an excuse," Rasner said. "I was garbage today, and I'll be better next time."
Rasner walked two and struck out two, serving up a two-run shot to Kevin Millar in the second and a three-run blast to Paul Bako -- the catcher's first since Aug. 21, 2004 -- in the fourth.
"It gives me a baseline of what I need to work on," Rasner said. "It's not the start I wanted, but I can't do anything about it now. I've got to move forward, take the positive from today and work to get better next time."
That has been a familiar theme one turn through the rotation, as the Yankees' starting staff has not performed up to expectations. Only certain bullpen "saviors" -- as manager Joe Torre called them -- have stepped up to rescue the team with solid late-inning performances.
Just one starter, Kei Igawa, has pitched as many as five innings, and the left-hander surrendered seven runs in that start on Saturday. The most effective performance arguably came on Opening Day from right-hander Carl Pavano, who lasted just 4 1/3 innings in his first big-league appearance since June 2005 and will try his luck again on Monday at Minnesota.
"As long as we're able to not pitch the same guys every day, I think we'll get through it," Torre said. "But for certain, you don't want to have this on a steady diet. That's certainly not going to mean a good year if that's the case."
The Yankees' taxed bullpen used Sean Henn, Scott Proctor, Mike Myers and Luis Vizcaino again on Sunday, but received a break from an unlikely contributor, as Andy Pettitte turned in a rare relief appearance.
Pettitte pitched the sixth inning in his first relief appearance as a Yankee since Sept. 25, 1998, though he did appear in relief for the Astros last season and has now made nine such appearances. Pettitte said that it wasn't much of an adjustment to scrap his scheduled bullpen session in favor of a game appearance.
"The bottom line is, we've got to get through these games and just do whatever you've got to do to get through them," Pettitte said.
The left-hander said that he'd approached Torre on Saturday with the idea of lending a helping hand in relief. Given how word of Rasner's blister issues moved up and down the bench, Pettitte expected to be in even earlier.
"We're short right now, and I needed to throw today and I could," Pettitte said. "I'm just glad I was able to give us an inning."
With the Yankees keeping him to a strict 15-pitch limit, Pettitte blanked the Orioles in the sixth around a walk to Melvin Mora, and recorded a strikeout. He is still considered probable to pitch as scheduled on Tuesday against the Twins.
"We finally had to shove him down the [dugout] runway," Torre said.
The Yanks scored first in Sunday's contest, with Bobby Abreu getting a sacrifice fly and Alex Rodriguez blasting a two-run homer in the first inning off Baltimore starter Erik Bedard. The home run was Rodriguez's third in the last two games and his second in consecutive at-bats, having hit a game-winning grand slam to defeat the Orioles on Saturday.
Torre said that watching Rodriguez during this homestand -- he's batting .381 with four homers and 11 RBIs as the Yankees leave town -- has been fun, noting a lack of hesitancy in Rodriguez's swings.
"I'm having a good time," Rodriguez said.
Bedard settled in after the Rodriguez home run, retiring 11 in a row and blanking the Yankees over the next six innings. Bedard pitched seven innings, scattering five hits while walking none and striking out five.
"He can mix it up," Torre said. "He's not hesitant about throwing the breaking ball behind in the count, and he has a couple of different breaking balls. He's got a fastball that he can get in to right-handers. He's the complete package, he really is. He's really impressive."
The Orioles tacked on a run in the seventh inning off Scott Proctor. Miguel Tejada reached second on a Robinson Cano error and scored on Millar's sacrifice fly, his third RBI of the game.
Coming in off the bench, Johnny Damon tripled off Jamie Walker in the eighth and scored on a Melky Cabrera groundout, but a potential rally died in the eighth when John Parrish induced Josh Phelps to fly out to center field with the bases loaded.
Chris Ray finished off the Yankees in the ninth inning around a Damon single for his second save of the series, locking up Baltimore's successful weekend.
"They played better than us, that's what it comes down to," designated hitter Jason Giambi said. "Hopefully, we'll get going on the road."
Bryan Hoch is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.