Shoemaker retired the first 11 Kansas City hitters he faced before allowing a double to Lorenzo Cain with two outs in the fourth inning. The Royals won 8-4.
Shoemaker would have better reason than most to be nervous on the mound. In his final start last season, Sept. 4 in Seattle, a 105 mph line drive off the bat of Kyle Seager struck him just above the right ear.
Shoemaker was able to walk off the field, but he required emergency surgery after tests revealed a skull fracture and bleeding in his brain.
He said he has felt "pretty normal" when balls are hit up the middle in spring training.
"Anytime, whether you've been hit before or not, I feel like when a ball comes back toward you, you flinch," Shoemaker said. "It's just a natural reaction to put your glove up to try to catch it. So definitely, I don't think any different than normal."
Shoemaker is trying out a couple of protective plates in his hat this spring.
"Messing with both of them, seeing which one I like," he said.
He needed only 41 pitches for four innings. He threw another 15 to 20 pitches in the bullpen after being removed.
"I'm just continuing the process this spring, getting ready," he said.
Shoemaker won 16 games in his 2014 breakout season and went 9-13 with a 3.88 ERA last year.
Royals C Salvador Perez returned to Arizona and had a second MRI Tuesday on his left knee, which he injured Saturday in the World Baseball Classic. Kansas City manager Ned Yost said after the win that he had no reports on Perez's medical tests.