PITTSBURGH -- Pirates setup man Neftali Feliz left Saturday night's game against the Brewers at PNC Park in the eighth inning due to right arm discomfort, the tipping point of an ugly frame that led to Pittsburgh's 7-4 loss, the club's fifth straight.
Feliz gave up singles to two of the three batters he faced then grimaced in pain after throwing a pitch to Milwaukee center fielder Kirk Nieuwenhuis. Pirates assistant athletic trainer Ben Potenziano ran out to the mound, where Feliz clearly looked uncomfortable. He then left the game.
The right-hander hadn't pitched since Monday, when he was hit hard but also struck out three batters in one inning against the Cubs. Pirates manager Clint Hurdle said he heard "absolutely nothing" to indicate that Feliz had been pitching through an injury.
Catcher Francisco Cervelli said he didn't see anything unusual from Feliz until after the pitch to Nieuwenhuis.
"Just that pitch, his body language was different, and I had to go out there," Cervelli said.
The game unraveled shortly after Feliz walked off the mound. Left-hander Felipe Rivero replaced him in a tie game with runners on the corners, walked Jake Elmore, then gave up a go-ahead single to Orlando Arcia.
Rivero, who has been excellent since joining the Pirates in late July, later gave up a two-run single to Manny Pina that put the Pirates in a three-run hole. Hurdle didn't think the quick call to action affected Rivero.
"Guys in the bullpen know that they can be called upon," Hurdle said. "He's been a guy that's pitched in those situations with inherited runners and hadn't let one score until tonight."
Lefty Kelvin Marte, making his Major League debut, entered and allowed another run to score. And whatever momentum Pittsburgh gained over the previous two innings, when Jared Hughes escaped a bases-loaded jam and Andrew McCutchen hit a game-tying solo homer, had disappeared.
"There was still a lot of baseball to be played," Hughes said.
Feliz has dealt with injuries in the past. He had Tommy John surgery in 2012 that also shortened his '13 season. He appeared in only 30 games in '14, and injuries impacted his performance last season, when he posted a 6.38 ERA for the Rangers and Tigers.
Feliz has been a reliable setup man for the Pirates, first in the seventh inning in front of former closer Mark Melancon and more recently in the eighth before Tony Watson. The 28-year-old entered the night with a 3.21 ERA in 61 appearances, striking out 61 batters in 53 1/3 innings.
"He's been awesome for us this year," Hughes said. "He's been a horse for us, and hopefully he can continue to be a horse for us."
If Feliz is out for any extended period of time, the Pirates will view it as another obstacle to overcome in a season full of them.
"A lot of people say every time they take somebody out of here, we're done. We've got to keep battling," Cervelli said. "They took Melancon out. They took [Francisco] Liriano. We're still here. I hope he's fine. We're going to keep battling, because we've got one mission."
Adam Berry has covered the Pirates for MLB.com since 2015. Follow him on Twitter at @adamdberry. This story was not subject to the approval of Major League Baseball or its clubs.