So while Cahill knows he'll be a spectator, Bailey realizes that he could be summoned at almost any time to face the National Leaguers. That knowledge made him a bundle of nerves at last year's All-Star Game, when he made the AL team as a rookie.
"I was sitting down there in the bullpen, and in the first inning I was sweating already," Bailey said. "I was so nervous. Hopefully this year I'll be able to kind of hone everything in a little bit more and not be as nervous. ... I know my chances of pitching are pretty good. If I get in there, I'm going to take full advantage of the opportunity to represent my bullpen and the Oakland Athletics organization. If I don't get in there, I'm not going to be disappointed. It's just awesome being here and being acknowledged by [AL manager] Joe Girardi and Major League Baseball."
Bailey didn't appear in the AL's 4-3 triumph, but he still benefited from his visit to St. Louis. Merely watching proven pitchers such as Mariano Rivera, Jonathan Papelbon, Mark Buehrle and Joe Nathan go about their business deepened his insight into his craft.
"It was incredible to see how they go about their business and prepare for each and every game," said Bailey, 26. "We were just kind of hanging out and I was trying to act like I've been here before."
Now it's Cahill's turn to make the most of his inactivity.
Asked if he'll assume the traits of a sponge over the next couple of days, the 22-year-old Cahill said, "That's a good way to put it. I'm just here to soak it all in. I'm just trying to pick guys' brains, hang out with Bailey and talk to other guys and just have fun with it. I don't have anything to worry about."
Accompanying Bailey, who has been exposed to All-Star decorum and customs, is invaluable for Cahill. "I'll probably be his shadow most of the time," said Cahill, who's 9-3 with a 2.94 ERA in 15 starts.
That's not unusual for Bailey and Cahill, who are roommates when the A's are at home. They share a place about 20 miles northeast of Oakland in Walnut Creek.
Both also have encountered obstacles en route to All-Star status.
Cahill wasn't even on Oakland's Opening Day roster. He began the season on the disabled list, forced to deal with a stress reaction near his left scapula. Upon recovering, he was sent to Triple-A Sacramento, where he made two starts before being recalled to fill in for the injured Brett Anderson.
"He got on a roll with his command this year, and he was able to make adjustments with left-handed hitters.
"That's been the biggest difference for him," A's manager Bob Geren said of Cahill, who finished 10-13 with a 4.63 ERA last year. "With the left-handed hitters, he's really turned that around 180 [degrees]."
Bailey has glided along a hurdle-free path this season en route to receiving an invitation to the AL roster to replace the Angels' Jered Weaver, who replaced Cahill. But Bailey overcame a measure of anonymity slightly more than a year ago, when he was completely off the baseball radar.
Bailey was a 2009 non-roster invitee to Spring Training after salvaging his 2008 season with a move from Double-A Midland's starting rotation to the RockHounds' bullpen. In a meteoric rise, Bailey not only made the big league club but soon found himself in the coveted closer's role and, ultimately, on the All-Star team as the A's lone representative.
"I think where Trevor started this year, at Triple-A, with some uncertainty, I guess you can kind of compare it to what I went through last year," Bailey said. "It was a whirlwind for me, making the team and having success come from that. It's kind of the same thing with him, not knowing if he was going to make the team. For him to start the year on the DL and then go to Triple-A and come up here and prove that he does belong, that just shows what character and confidence he has in his stuff, and what the organization thinks of him."
Bailey and Cahill give the A's multiple All-Star representatives for the first time since 2004, when pitchers Mark Mulder and Tim Hudson joined forces. Bailey also is the first A's player to earn back-to-back All-Star accolades since Mulder did so in 2003 and 2004 and the first A's closer to make the team in consecutive seasons since Dennis Eckersley in 1991-92.