ANAHEIM -- Until further notice, lefty Brian Fuentes and righty Grant Balfour will reverse roles in the bullpen.
Fuentes will shift to setup duties, while Balfour will be the team's closer.
"I told Brian, that for now, until he has a few good outings in a row, that I would stick with Balfour," manager Bob Geren said before Tuesday's game in Anaheim.
The switch follows a rough stretch for Fuentes, who has been charged with the loss in each of his past four games. Owner of a 1-7 record and 5.06 ERA, the veteran southpaw is the first reliever to have seven losses before June 1 since Gene Garber also tallied that many in 1979 with Atlanta, according to the Elias Sports Bureau.
Balfour, meanwhile, had not allowed a run in 14 games -- spanning 14 1/3 innings -- until Sunday, when he offered up a game-tying home run to the Giants' Nate Schierholtz in San Francisco.
The gritty right-hander has not allowed a run in 19 of his 22 appearances this season and has surrendered just five total in 21 2/3 innings for a 2.08 ERA. He's tied for fourth among American League relievers in strikeouts (26) and has held opponents to a .192 batting average.