OAKLAND -- Asked to prepare as a starter this season, Adam Warren's objective was to prove to the Yankees that he was ready to handle the assignment on a regular basis. His subsequent excellent performance in the spring made a rotation nod a mere formality.
Now, as the Yankees prepare to figure out how six pitchers best fit into five slots, Warren has stated his case with his four sharpest starts of the season. The right-hander hurled seven innings of two-run ball, yet was hung with the loss in a 3-0 loss to the A's on Sunday.
"I feel like I've gone out there and competed, and given the team a chance to win," said Warren, who is 3-4 with a 3.75 ERA. "That's my goal every time out. I don't have any regrets about what I've done, and I feel like I've gotten better. So I'm pleased with that."
Making his 10th start of the season and the 13th of his career, Warren scattered six hits with a walk and four strikeouts, with his only major blemish coming on Stephen Vogt's sixth-inning homer to right field.
"He pitched really well," Yankees manager Joe Girardi said. "He made a mistake. He made one mistake, and unfortunately, it cost the game. We got a really good performance out of him, and unfortunately, we didn't score any runs."
Otherwise, Warren continued doing what he has done over the last two-plus weeks, a span in which he has permitted nine earned runs in 26 2/3 innings (3.03 ERA). The Yanks must make a move to accommodate Masahiro Tanaka's return from the disabled list on Wednesday in Seattle, and Girardi said that call has not yet been made.
While left-hander Chris Capuano (0-3, 6.39 ERA) has hardly distinguished himself in three starts since returning from the disabled list, Warren's previous success in the bullpen may work against him in this case.
The Yanks are already carrying four left-handed relievers, which Girardi said they want to do at least through the Seattle series, which starts Monday night. Warren could present an option to shore up the weaker parts of the right-handed bullpen corps, with Esmil Rogers (4.70 ERA) and David Carpenter (5.00 ERA) struggling.
"He's pitched well," Girardi said of Warren. "As I've said, we'll sit down and talk about it and make a decision and go from there."
Bryan Hoch is a reporter for MLB.com. Follow him on Twitter @bryanhoch, on Facebook and read his MLBlog, Bombers Beat. This story was not subject to the approval of Major League Baseball or its clubs.