However, both Maholm and general manager Neal Huntington emphasized that the setback is nothing to be concerned about even with the regular season just three days away.
"If this were the regular season, he would have started," Huntington said. "It's the second-to-last game of Spring Training. There's no need to push anything at all."
Said Maholm: "It's nothing serious."
Though originally scheduled to start the team's third game of the regular season next Thursday in Atlanta, Maholm will now take the mound two days later against the Marlins instead. Zach Duke, originally slated to pitch that Saturday in Florida, will swap places with Maholm in the rotation.
Maholm threw long-toss early Friday morning and reported no discomfort afterward. He is scheduled to throw a bullpen session during the team's workout in Atlanta on Sunday and then will throw a simulated game during Tuesday's off-day.
Maholm was sidelined for a short time near the end of last season because of stiffness in his lower back, though the Pirates are not worried that this latest episode will prove to be as serious.
The 25-year-old left-hander made five starts this spring, with his most dominant performance coming in his start last Sunday. Maholm allowed just two hits in six scoreless innings. Overall, he gave up eight runs and stuck out nine in 20 innings of Grapefruit League work.
Phil Dumatrait will make the start in place of Maholm in the team's Spring Training game against the Twins.
Jenifer Langosch is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.