The 22-year-old right-hander is 8-2 with a 2.74 ERA in 13 starts this season but is slated to start on Sunday against the Angels, making him ineligible to play during the All-Star Game.
Yankees skipper Joe Girardi, this year's manager for the American League All-Stars, was asked before Monday's game at Oakland what he plans to do if Cahill pitches on Sunday.
"We'll look at all of the players that are out there," Girardi said. "Trevor Cahill has thrown the ball extremely well. He'll still be an All-Star, and he'll still represent the A's there. If he pitches Sunday, obviously he won't be able to pitch, so we'll look at other guys."
Since Cahill is currently Oakland's lone representative this season, A's manager Bob Geren said he hopes the A's can have another player participate. Geren, who will be a coach for the All-Star Game, said he hadn't talked to Girardi as Monday afternoon.
Asked if he felt obligated to tab another A's player in Cahill's stead, Girardi said, "I think what you'll do is look at the most deserving pitcher to go next."
Geren has voiced his support for catcher Kurt Suzuki and a couple of A's relievers -- closer Andrew Bailey and lefty Craig Breslow. Bailey entered Monday having converted 17 of his 20 save opportunities this year, with a 1.59 ERA. Breslow, meanwhile, had a 2.84 ERA in 40 appearances this season. Suzuki entered Monday batting .255 with 35 RBIs and a team-high 10 home runs.
"I know Bailey's had a great year again, so I was kind of surprised it was me and not him," Cahill said. "But I think we have a lot of deserving guys on this team, and this year, I was lucky enough to go."