The 24-year-old threw 38 pitches, 27 for strikes, across two innings against the Kansas City Royals at Kauffman Stadium. Righty reliever Drew Hutchison replaced him for the third inning.
“I thought it was precautionary to shut it down,” Manning said.
“Hopefully, it’s just a matter of cold (weather) and him feeling a little bit fatigued or achy or whatever,” Tigers manager A.J. Hinch said. “We’ll obviously get him evaluated.”
TIGERS INJURIES: Javier Báez on injured list; Casey Mize’s elbow shows ‘good sign’
The severity of Manning’s shoulder injury is unclear, but the 2016 first-round draft pick isn’t worried about his health.
“I’m not very concerned,” Manning said. “I think it was good to just get a short one in today so I can use the extra day, get more rest, get it flushed out of there and get back on the bump.”
He lunged for two groundballs, including on a groundout from Whit Merrifield to end the second inning that deflected off Manning. The ball was picked up by Harold Castro, who threw out Merrifield at first base.
“Honestly, I should’ve had both those plays,” Manning said. “I’m a Gold Glover, man.”
Manning allowed one run on five hits in his two innings. He struck out two batters, without conceding a walk, and registered five swings and misses, including two curveballs and two sliders.
“I’m just more frustrated that I couldn’t finish,” Manning said. “I tried to stay in there.”
His fastball averaged 92.9 mph.
“His fastball didn’t have the life like it usually does,” Tigers catcher Dustin Garneau said. “I caught his bullpen a few days ago, and it was electric. Catching him today during the game, it didn’t have the extra gear like it usually does. If he’s sitting 90-91 (mph) for us, and there’s not the obvious visual life that it usually has, it’s definitely different than when he’s hitting five and six (95-96 mph).”
The Tigers placed right-hander Casey Mize on the 10-day injured list Friday with a right elbow sprain. Mize, also 24, reported elbow soreness after Thursday’s start in the series opener against the Royals.
Mize will miss at least one start, which is Wednesday against the New York Yankees at Comerica Park. Right-hander Michael Pineda is expected to enter the starting rotation and pitch that game.
Manning has a 2.25 ERA with zero walks and four strikeouts across eight innings in two starts. He pitched six innings of one-run ball against the Boston Red Sox in his first outing.
On Saturday, Manning couldn’t make it to the third inning.
“He didn’t quite look right,” Hinch said of Manning. “We asked him about it when he got to the dugout after the second. He said he was fine to pitch through it, but he was feeling a little something in his shoulder. Coming on the heels of the last 24 hours, we weren’t going to take any risk whatsoever, so we got him out of the game.”