Capps, 22, pitched one perfect inning at Rangers Ballpark last season after getting called up midseason, so he's familiar with the hitter-friendly stadium, but he says it doesn't change anything for him.
"They all work the same, if you keep it on the ground and they hit it at somebody," he said. "Even in Safeco, the ball still flies. It's not like dead air. You've got to keep the ball down everywhere."
With Stephen Pryor on the disabled list, Capps has moved into the late-inning setup role in the bullpen. He threw the seventh and eighth innings on Thursday before turning it over to closer Tom Wilhelmsen.
"I still have to put up zeros, no matter what inning," Capps said. "If I go in the third, I'll try to put up zeros. I don't want anybody to score. I don't mind if they get on, but if they cross the plate, we've got a problem. That's my mentality."
And after pitching back-to-back games, including Thursday's 40-pitch outing, he's ready to keep rolling.
"If that phone rings tonight and they call my name, I'll be ready to go," said the North Carolina native. "I love it."
But manager Eric Wedge said he needs to be careful with not overworking the youngster. The makeup of the bullpen has changed dramatically with Yoervis Medina, Hector Noesi and Blake Beavan now the right-handers behind Wilhelmsen and Capps, now that Pryor and Josh Kinney are on the disabled list and Kameron Loe was designated for assignment.
"Our bullpen has different people down there right now," Wedge said. "He really stepped up for us [Thursday] and we're going to need other people to step up, too. We can't pitch him every night."
Greg Johns is a reporter for MLB.com. Follow him on Twitter @GregJohnsMLB as well as his Mariners Musings blog. This story was not subject to the approval of Major League Baseball or its clubs.