But by the time he was in high school, Garrett took up basketball.
"I didn't pick up basketball until ninth grade. I had never played basketball in my life," Garrett said. "A lot of my friends played basketball. I'd spend the night at my friends' house and play basketball. We really didn't play baseball. It was so much easier for me to migrate to basketball. I couldn't say, 'Hey guys, do you want to play baseball?' It was 'Let's get the basketball, go to the gym and go shoot.' It was that easy."
Quickly, Garrett became a sought-after basketball recruit, who would eventually attend St. John's University in New York. As a high school senior, he won a national slam dunk contest.
"I won with a 360 off the side of the backboard. I can't do that anymore," Garrett said.
Garrett, now 24, never fully turned his back on baseball. He continued to pitch in games and show the ability that attracted big league scouts.
"Every time I would go back, I would pitch and have 11, 12, 13, 14 strikeouts and be, 'Oh, this pretty cool,'" Garrett said. "Then I would put it on the backburner and go play basketball again."
Garrett couldn't shake baseball permanently, in part, because of the memory of his grandfather, Mack Wysinger, who went by "Pops." Wysinger died when Garrett was in eighth grade.
It was Pops who turned Garrett on to baseball, and he never forgot.
"He's the one who taught me how to play baseball since I was knee-high," Garrett said. "He made me be a left-handed pitcher. He was left-handed as well. I used to be able to throw with both hands when I was younger. His first love was baseball and he wanted me to be a baseball player, as well."
Even while he was playing college basketball, the Reds took a chance and made the 6-foot-5 Garrett a 22nd round pick in the 2011 Draft. He played both sports for a couple of years, but finally focused full-time on baseball by 2014.
Garrett's baseball career went into another gear and he moved up quickly. He is now Cincinnati's No. 2 prospect, according to MLBPipeline.com, and vying for a spot in the big league rotation this spring.
"Baseball is where it's at, man," Garrett said. "When I was playing basketball, it was really hard to juggle both sports. It was taking a lot of wear and tear on my body, my legs and everything like that. When I had a good year, it was like baseball was my calling."
Under his cap, Garrett has the word "Pops" written on the bill for the man who made that calling possible in the first place.