Manager Bob Melvin announced a role change for the ninth inning, saying that right-hander Chad Qualls has been elevated to the closer’s role in place of the struggling Brandon Lyon.

The change might not go into effect until Sunday because of Qualls’ workload, in which case Tony Pena would serve as closer for tonight’s game.

Lyon had a 2.43 ERA and 19 saves in 23 chances at the All-Star break but has not pitched well since. In the second half, he has an 11.57 ERA (21 earned runs in 16 1/3 innings).

Despite Lyon’s struggles, Melvin said it wasn’t an easy move to make, in part because of how Lyon is viewed by his teammates and his role in the clubhouse.

"There’s also a personal side to it, too, and Brandon is a star down in that bullpen," Melvin said. "He’s a leader down there. He’s about as accountable of a guy as I’ve ever had in the bullpen. He totally understood when I talked to him today and all he wants to do is help his team win. In that respect, he took it like a pro."

Qualls came in to bail out Lyon on Friday night, getting the final out of a 3-2 win over the Reds by striking out Jerry Hairston Jr. He has been the bullpen’s best pitcher for the past several weeks.

Qualls has not been scored upon in 17 of his past 18 appearances and has a 1.02 ERA since Aug. 6. He has a 3.11 ERA on the season, but has eight blown saves working in a setup role. He also has eight losses.

But Melvin said that since Qualls has pitched in four of the past six games -- and warmed up in one of those games in which he did not pitch -- he probably won't be available to close tonight. In that event, Juan Cruz would likely pitch the eighth inning with Pena closing.

Melvin said he would like to give Lyon tonight off before inserting him into a setup role.