Fiers exited soon after being hit in the left shin in the second inning, and the Detroit Tigers relied on their bullpen to beat the Cincinnati Reds 7-4 Wednesday for a two-game series sweep.
"That was supposed to be easy," Tigers manager Ron Gardenhire said.
Fiers was struck by a liner from Mason Williams, who wound up with a single when the ball caromed toward the first base line. Fiers finished the inning but didn't come out for the third.
"It wasn't too bad -- it is just a bruise -- but I couldn't really land on it," Fiers said. "The guys here didn't want to risk me changing my delivery and hurting my arm."
X-rays on Fiers' shin were negative. It was unclear whether he will make his next scheduled start.
"We're going to see how he is," Gardenhire said. "It swelled up pretty big."
Drew VerHagen (2-2) followed as the first of six relievers and pitched three scoreless innings.
"He had his good sinker going tonight, and that's tough for a hitter to get the barrel on," Tigers catcher John Hicks said. "Even if they do make contact, they are going to drive it into the ground."
Shane Greene pitched the ninth for his 23rd save in 26 chances.
Sal Romano (6-9) allowed four runs and eight hits in 5 1/3 innings.
Cincinnati also threw away two relay throws to the plate, both allowing runners to advance on the bases.
"That was just bad baseball," Reds interim manager Jim Riggleman said. "It is great effort, but bad performance. We have to find a way to clean that up."
"It was just not a good baserunning play on my part," Casali said. "The hesitation cost me. I wish I could go back, because that was a rally-killer on my part."
Rodriguez, who replaced Adduci in the sixth, finished with two hits and two runs. Adduci also had two hits, including the homer.
"That's great strategy, I guess," Gardenhire said. "They went to the lefty, and Rodriguez was the obvious move, but he made me look good."
"I put my hand up like I was going to catch it, and that froze him," said Jones, a converted shortstop. "After that, I was just playing it like an infielder and trying to make a good throw."
Reds: With OF Scott Schebler (right shoulder) still waiting to start a rehab assignment and OF Jesse Winkler having season-ending shoulder surgery on Tuesday, Tucker was Cincinnati's designated hitter and will see action in the outfield.
Tigers: LHP Francisco Liriano is scheduled to start Sunday in Oakland. The allergic reaction that caused him to miss his first start after the All-Star break was finally determined to be caused by a chemical used on his lawn in Miami.
Could these 'mystery teams' be in on Manny Machado, Bryce Harper?
Are the Yankees set to swoop in on Manny after all? Who might be biding their time for Bryce? We look at some of the potential surprise suitors insiders are talking about.
'I came up on one-year deals': How Joe Maddon is approaching 2019
As the skipper enters his potential final year in Chicago, Maddon is leaving no stone unturned as he tries to get the Cubs back on track after a disappointing finish and a quiet offseason.
Will Bryce Harper and Manny Machado sign before Super Bowl Sunday and other burning questions
With the offseason providing few answers for baseball's superstar free agents, we shed some light on where things stand and where they're headed.
Yankees' DJ LeMahieu says he'll bring many gloves to spring training
DJ LeMahieu said Wednesday he's ready to be used at multiple positions by the Yankees, who signed the three-time Gold Glove second baseman to a two-year contract.
Machado will take financial hit due to World Series drama
Karl Ravech explains the White Sox's 7-year, $175M offer to Manny Machado and why Machado may not get the $300M deal he wants.
Mets newcomer Jed Lowrie ready to play all over the diamond
Jed Lowrie would rather talk about wine than whine.