But Garrett was able to busy himself with some shopping and a nap before coming to the ballpark. Once he stepped into the clubhouse and later, onto the mound, his nerves were checked at the door. The 24-year-old tossed six stellar innings in a 2-0 Reds blanking of the Cardinals.
"When I came to the ballpark, I just told myself it's another game," Garrett said. "I came in here and talked to the guys, got a couple laughs out of Finny [Brandon Finnegan], Rookie [Davis], talked to them. I just went out there, and just had fun with it."
Garrett allowed two hits and two walks with four strikeouts. No Cardinals batters reached second base when he was on the mound. He was the third Reds pitcher since 1913 -- and the first since Wayne Simpson in 1970 -- to throw six or more scoreless innings in his big league debut. It was also the first time a Reds pitcher debuted with a win against St. Louis since Keith Brown on Aug. 25, 1988.
Of the 78 pitches Garrett threw, 40 were his four-seam fastball, and it averaged 91 mph and topped out at 93 mph according to Statcast™.
"Today I was mostly fastball-changeup to lefties," Garrett said. "I [threw] a slider a little bit. I was able to spot up my fastball really well today, going in and out, up and down. My changeup was really good today. That was the pitch for me [used five times] I felt was the key of the game."
All the while, he seemed in complete control of his pitches -- and emotions. Following a walk to his first batter, Garrett retired seven in a row and 10 of the next 11.
"Extremely mature and polished young guy. That was a very impressive debut," Reds manager Bryan Price said. "From what I've seen of Amir, and most of that was this spring and obviously tonight, he just doesn't self-inflict and doesn't get himself in trouble, and not trusting his stuff. He has great faith in his ability, and that allows everything he does to play up a notch."
The Reds No. 2 prospect, and No. 64 overall, according to MLBPipeline.com, Garrett won a rotation spot with a strong spring. Despite a sojourn into high school and college basketball from ninth grade until 2014, Garrett focused full time on baseball by 2014, three years after the Reds made him a 22nd round pick in the 2011 Draft.
Playing basketball in New York for St. John's University was an experience Garrett could draw on in front of 44,653 fans at Busch Stadium.
"It helped me a lot," Garrett said. "When I went out there, it was 'I've been here before, just a different sport.' I was able to look around for a second and just see everything. I took it all in stride. I was very happy. It worked out well today."
Mark Sheldon has covered the Reds for MLB.com since 2006, and previously covered the Twins from 2001-05. Follow him on Twitter @m_sheldon and Facebook and listen to his podcast. This story was not subject to the approval of Major League Baseball or its clubs.