But in the two starts since, he has allowed only four runs on nine hits in 14 innings, and with Wednesday's win over the Cubs, improved to 8-6 with a 2.85 ERA.
"I never felt like I was off track," Fiers said.
He delivered 7 1/3 innings of one-run ball in Chicago, striking out six while walking only one.
"Things like that happen in this game, and you just have to push them aside and work and get ready for your next start," Fiers said. "I just kept doing the things I was doing."
Marlins starter Ricky Nolaso is on a recovery of sorts as well.
Nolasco threw a shutout over the Nationals on Tuesday -- his first this season and third of his career. The gem came after two consecutive outings in which he allowed five earned runs.
"I'm not trying to do too much," Nolasco said of his last start. "It is kind of funny the way the game is. I felt terrible warming up and stuff. It's the same old story, when you feel great, and are trying to do too much, you start leaving the ball over the plate. And there are times when you feel terrible, and you're kind of mentally set where you're not trying to do too much. You end up hitting spots and stuff, and things work out better for you."
Nolasco has struggled against the Brewers throughout his career, and though he has yet to face them in 2012, he is 1-2 with a 9.47 ERA over six career starts.
Brewers: Narveson begins throwing program
Left-hander Chris Narveson, who has been sidelined since April with a season-ending shoulder injury, has begun a throwing program and is hoping to resume mound work before the season comes to a close.
On Sunday, Narveson played catch for the fourth time since his May 1 surgery for a torn rotator cuff.
"We're just playing catch right now, just like we're getting ready for a season," Narveson said. "Hopefully, by the end of the season, we're just starting to get off a mound."
Marlins: Stanton returns to cleanup spot
Giancarlo Stanton battled cleanup on Sunday for the first time since coming off the disabled list on Aug. 7.
In 23 games since his return -- Stanton underwent surgery to remove two cartilage chips in his right knee on July 8 -- the slugger was batting .310 with 10 home runs and 23 RBIs, all out of the fifth spot in the lineup.
Hitting coach Eduardo Perez said Stanton should take the same approach regardless of where he hits in the lineup.
"I don't want him to change anything," Perez said. "I want him to stay the same. I want him to just play his game, and just realize that his game is exactly what we need. We don't need more, we don't need less. We just need him to be himself."
With his second-inning single, Marlins second baseman Donovan Solano has now hit safely in 14 of his last 15 games.
Jose Reyes' two stolen bases on Sunday moved him past Emilio Bonifacio for the team lead. Reyes now has 32 steals this season.