There was a time when Manny Parra knew his name would be penciled in every fifth day for the Milwaukee Brewers, counted on to go deep into games and preserve the bullpen as best he could.

Now, Parra heads to the ballpark with a different feeling, an excitement that on any given day manager Ron Roenicke will call for him to replace a teammate on the mound.

"I know I like to work a lot because I think it helps me deal with that muscle memory," Parra said. "I can get off mechanically, mentally and just getting the work kind of keeps you focused on the game and doing those consistent things. Obviously if I'm pretty sore I'm not going to go but I like getting in there. I like coming to the field knowing that I might get in the game."

He's been called up on quite a bit over the last 13 days, with his emergency relief of injured starter Marco Estrada on Wednesday marking his seventh appearance over that time frame.

The tall, 29-year-old lefty was once one of the crown jewels of the Brewers organization as a starter, but after suffering through a variety of surgeries in 2009, 2010 and missing all of 2011, he has been reborn as reliable option in relief.

"I feel good. My arm feels healthy," he said. "The one thing I struggle with here and there is my back. It's funny, in sports you know you hear guys are always playing hurt so maybe ... I'm about to be 30, so I'm assuming this is just the road that everyone else is taking and you kind of learn to manage those things and deal with them. So far I've been able to."

While Parra's medical file may differ from his teammates down in the bullpen, all of them have been learning how to manage the health of their arms the last two weeks.

Thanks to a combination of extra-inning games and shortened starts, the entire relief corps has been pushed to its limit since May 11. Kameron Loe and Jose Veras made their seventh appearances in that time frame in relief of Parra Wednesday while John Axford made his sixth.

Francisco Rodriguez and Tim Dillard have been on five times.

Juan Perez, who was called up on Saturday, appeared in four straight games before Wednesday's day off.

"It's tough when we need these guys all the time," Roenicke said. "I'd much rather give some of these guys a little better rest. I haven't really been around that, at least for a long time, maybe since when I was playing (in the 1980s)."

Despite Roenicke and pitching coach Rick Kranitz's concerns over the workload, the mood in the bullpen has been good.

"We compete," Rodriguez said. "I know there are a couple guys that have been throwing a lot, and get up (with) a lot of dry humps too, but we've been available to pick each other up, which is something really nice."

Parra agreed, saying one another's success – and failure – has strengthened the resolve of the group to answer when called upon. On six occasions, at least one reliever has been asked to pitch on back-to-back days, while Veras and Perez have each appeared in three straight at one point.

"We have a lot of desire, a lot of frustration down there where it's motivating us to get into games every day because we want to do better," he said. "I wasn't on the team last year, so obviously I didn't get to see the way they handled it, but the guys here you don't hear any complaining, guys are just relaxed, we try to have fun and keep it loose, but at the same time when it's time to be called you don't see a guy who doesn't want to get in the game."