PHOENIX -- Mike Fiers was scratched from a scheduled start against the Giants on Thursday with right shoulder fatigue, though he was still able to throw a bullpen session at Maryvale Baseball Park. Fiers and manager Ron Roenicke each characterized the issue as minor.
"Obviously, not alarming because he's throwing a bullpen today," Roenicke said. "We just feel like there's a couple of days, depending on how the bullpen [session] goes, to where he'll start again."
Fiers said he hoped to pitch in a game as early as Saturday. Kyle Lohse is currently scheduled to start against the Rangers that day in Surprise, Ariz., and the Brewers' Triple-A and Double-A teams play home games against Angels affiliates.
The Brewers do not believe Fiers' setback will force changes to the regular-season rotation, which has Fiers in the No. 4 position. He would pitch April 10 against the Pirates at Miller Park, but could be bumped back a day if the Brewers want to use Jimmy Nelson ahead of Fiers.
Because of early-season off-days, the Brewers also could opt to go without a fifth starter until April 20, if necessary.
"But right now, we're planning on [Fiers throwing] the bullpen here and we really don't lose anything," Roenicke said.
Fiers last pitched on Friday against the Mariners and surrendered four runs (three earned) on five hits and three walks in two innings.
Tyler Thornburg started in Fiers' place against the Giants. He has been stretching out this spring to be positioned as a backup option should an injury befall a member of Milwaukee's starting rotation.
"We'll just give it a couple of extra days," Fiers said. "It just wasn't feeling right in my bullpen [between starts]. You want to be 100 percent."
Adam McCalvy is a reporter for MLB.com. Read his blog, Brew Beat, and follow him on Twitter at @AdamMcCalvy. This story was not subject to the approval of Major League Baseball or its clubs.