ST. PETERSBURG -- Manager Joe Maddon feels as though he's getting a clearer understanding of his bullpen.

Throughout the course of Spring Training, he said, teams don't really use their 'pens the way they would during the regular season, because it's all about getting guys the proper amount of innings so they can be ready once April rolls around.

Maddon is known for being very fluid with his bullpen -- he likes to mix it up and play to the best matchup rather than slot a reliever into a certain role. Now 25 games into the season, though, Tampa Bay's skipper is getting a feel for how to use his guys -- especially new additions Brian Shouse and Joe Nelson.

"You come into the season, and you have these two new toys to play with, and you really like them, but you don't know when to pull them out of the toy chest," Maddon said. "You're looking at it now, and I have a better idea of both of these guys, and you also see where the guys are from last year."

Despite a setback on Saturday -- when Grant Balfour and Shouse combined to give up four runs in a 1 2/3-inning span -- the Rays' bullpen has been pretty good numbers-wise this season going into Sunday.

Despite going 0-3, the relief corps has posted a 3.84 ERA in 68 combined appearances. Tampa Bay's starters, on the other hand, are 10-12 with a 4.94 ERA.

"Everybody's starting to figure out their roles, and starting to figure out when Joe's going to use us," said Nelson, who's pitched back-to-back games but is available for Sunday. "He's trying to set us up for the best matchup."

In hopes of trying to get the most out of the bullpen, veteran closer Troy Percival has split the 'pen into two teams to see which side can go the longest without giving up an inherited run.

Nelson is paired with Balfour, Shouse and Dan Wheeler, so his team lost after Saturday's game, and the competition will reset for Sunday.

"[It's] just something Troy brought in so that every inning counts," Nelson said. "And I think that's part of the leadership of a guy like Troy. It doesn't matter if it's 10-1, or if you're winning or losing. It's a one-run game. Go out and do your job."