Phelps surrendered two-run homers to Todd Frazier and Jay Bruce and a two-out, RBI single to Michael Lorenzen in the Reds' 5-2 victory at Great American Ball Park.
"Hot day," Marlins manager Dan Jennings said. "[Phelps] didn't have the same command he's had in the past. He got on a pretty good roll there after the Frazier home run, and was able to execute some pitches. The changeup just stayed right in the middle of the plate, and Bruce got it."
That pretty much summed up Phelps' 104-pitch day on an 85-degree afternoon. The right-hander allowed five runs in 5 2/3 innings.
In his previous two starts, both wins, Phelps yielded two runs in 15 innings.
A walk to Joey Votto in the first inning, set up Frazier's opposite-field drive.
"Walked Votto in the first there," Phelps said. "I threw some pretty good pitches in that at-bat -- trying not to let him beat me. Got behind Frazier. I've got to make some pitches down-and-away to him. The pitch he hit out was just up enough."
A double play got Phelps out of a bases-loaded jam in the second inning.
"I settled into a little bit of a groove after I got the double play," the Miami starter said.
The homer to Bruce came on an elevated changeup.
"It's one of those things that on paper, the changeup to Bruce there, it's the right pitch," he said. "It's all about [execution]. The numbers are good until they're not. It's frustrating."