But when that shoulder is feeling flexible, as Siegrist's was Saturday evening, the pitcher is free to let loose.
In his second start back from the boredom of rehab and rest, Siegrist had a no-hitter before allowing a seventh-inning single in Class A Advanced Palm Beach's 3-0 win over the Jupiter Hammerheads.
"I felt really good, [my motion] felt really nice and easy," said Siegrist, who gave up five runs over 4 1/3 frames in his season debut last Sunday. "During the week, I worked with our pitching coach, Dennis Martinez, in the bullpen and little things made me feel more free when I was pitching. My arm slot, we dropped it down a little bit, made it more natural. It helps me throw my breaking pitches and off-speed pitches."
Siegrist (1-0) had retired 10 straight Hammerheads when Danny Black's single to right field broke up his bid for a no-hitter.
"You're always thinking about it. I'd be lying if I said I didn't," said Siegrist, who approached 80 pitches. "When I stepped on the mound, I put that in the back of my head and tried to make pitches.
"[Black] stuck with a slider that I thought was a pretty good pitch. He hit a soft popup and my outfielder tried to make a good play and it was just out of his reach. I was just like, 'OK, give me the ball.'"
The 22-year-old left-hander walked the next batter before being lifted. He struck out five while issuing two free passes and plunking one batter.
Set to bat when Siegrist exited? Hammerheads No. 3 hitter and Marlins No. 1 prospect Christian Yelich, who had struck out twice against the 2008 41st-round Draft pick.
"Showing my slider was really important to get him to back off my fastball," Siegrist said of his success in the matchup. "I feel like my fastball is my best pitch, so if I can get him off my fastball, it makes my other stuff that much better. I was taking one batter at a time. I didn't really think about him."
Iden Nazario also got Yelich out on strikes and induced an inning-ending double play to end the mini-threat. Nazario retired all three batters in the eighth before Dean Kiekhefer pitched a 1-2-3 ninth to earn his third save.
"That was nice to see," Siegrist said of his relief corps. "It pumps up the team."
The Cardinals scored all of their runs off starter Rett Varner (0-1) in the sixth. Mike O'Neill, Ronny Gil and Alan Ahmady singled to get the rally going. Ahmady went 3-for-4 and was the lone batter to collect more than one hit.
Varner allowed six hits and a walk before exiting with two outs in the sixth.
For Siegrist, this is a new beginning in an old stomping ground. He attended Palm Beach Community College and compiled a 3.42 ERA in 11 Florida State League outings last season after a dominant stretch in the Class A Midwest League.
Now that he's a regular in a Minor League rotation, the shoulder strain is no longer cause for concern.
"It feels great now," Siegrist said. "This definitely gives me confidence. I just got to take it into my next start."