PORT CHARLOTTE, Fla. -- During his sophomore season at Louisburg (N.C.) College, Seth Johnson spent an off-day in the batting cage at his school’s home ballpark. Then a light-hitting infielder frustrated by his lack of playing time and limited success at the plate, Johnson finished hitting and picked up a baseball. He hadn’t pitched since middle school, but he wanted to get on the bullpen mound and see what happened. 

Johnson flung a couple of fastballs as hard as he could. One of his teammates, Ethan Blevins, grabbed a Pocket Radar from his locker. After one pitch, the screen flashed 92 mph. That was the beginning of a journey that led to Johnson pitching at Campbell University, being picked 40th overall in the 2019 Draft and becoming one of the top-ranked pitching prospects in the Rays’ Minor League system.

“It was the best off-day of my life,” Johnson said, smiling, after the Rays’ Minor League Spring Training workout on Monday. 

Johnson asked to pitch every year he played at Jay M. Robinson High School, but his coaches never took him up on it. But after his impromptu throwing session, he realized he had a better chance to continue his playing career as a pitcher than a shortstop. Johnson talked his way into making five appearances as a pitcher during his sophomore season, and that opened the door for him to pitch as a junior at Campbell, where he displayed an easy delivery with two plus pitches that caught scouts’ attention. 

Johnson still has a couple bats in his apartment. They’re artifacts, at this point, of a prior career path.

“I’ll kind of pick [them] up and do one practice swing then be like, ‘Ah, that’s enough for today,’” he said, laughing. “Let’s stick to pitching.” 

Johnson made nine starts in Rookie-level leagues during his professional debut in 2019. The 23-year-old right-hander broke out in a big way for Low-A Charleston during the final two months last season, posting a 1.63 ERA with 66 strikeouts and only 14 walks in 49 2/3 innings over his final 11 starts. 

Johnson was admittedly never a great hitter, but he loved making tough, max-effort throws around the infield. “Pitching’s literally just throwing,” as he put it, so the transition made sense to him despite his lack of experience on the mound. He’s had to learn on the fly, asking a lot of questions and gaining game experience at the professional level. And after being sidelined for a year during the canceled 2020 season, Johnson said he basically had to relearn how to pitch last year. 

But last season’s stretch run offered a glimpse of the right-hander’s enormous upside.

“Arguably, for me, Seth Johnson was the best pitcher in that league the last six weeks,” said R.C. Lichtenstein, Johnson’s pitching coach in Charleston. “To watch him kind of finish that year was awesome, because in August and September, he was dominant. And it was fun to see.” 

Johnson credited a few people for the parts they played in his breakthrough performance. Lichtenstein helped him understand how to utilize his arsenal, specifically emphasizing the importance of throwing his fastball up in the zone and his mid-80s slider for strikes. Starter Ian Seymour helped create a blueprint for when Johnson should throw each of his pitches. And fellow breakout prospect Taj Bradley’s commitment to his routine inspired Johnson to study his own daily processes.

“Being able to watch that and learn how to use my pitches, I was able to take that and kind of put it into my own process, and everything kind of clicked,” Johnson said. 

Overall, Johnson finished last season with a 2.88 ERA and 115 strikeouts in 93 2/3 innings over 23 outings in Low-A. He was the Rays’ No. 16 prospect at the end of the year, according to MLB Pipeline, and he’ll leap into the organization’s top 10 list when this season’s rankings are released. 

Considering how little time he’s spent as a full-time pitcher, he’s still relatively raw. But that also means he might only be scratching the surface of his potential.

“It was really a confidence thing. Like once he realized he was fine, he took off,” Lichtenstein said. “Just to see him now in camp this year, and have the offseason he did, and realize he realized he knows who he is now, whereas last year he knew he had arm talent -- but he didn't realize he was a good pitcher yet.” 

The Rays realized it. So did other front offices. When rival clubs recognized that pitching prospects like Shane Baz and Bradley were likely off the table in trade talks last year, they set their sights on Johnson. But Tampa Bay held on to him, understanding the impact he could make in the rotation in a few years. 

“Nice to be wanted, but it’s even nicer the Rays kept me -- because I love it here,” Johnson said. “I love the coaches, love the coordinators, love my teammates. I was really happy I didn’t get traded.”

And there he was Monday morning on Field 1 at the Rays’ Charlotte Sports Park complex, stepping on the mound to throw live batting practice. As Johnson fired fastballs and sliders past his teammates, the crowd of onlookers grew to include high-ranking Rays officials like president of baseball operations Erik Neander, general manager Peter Bendix and vice president of baseball operations Carlos Rodriguez. 

Hard to believe the guy on the mound was a shortstop four years ago, right? 

“It’s definitely been interesting,” Johnson said. “Impossible to predict. I’m just enjoying every step.”