OAKLAND -- Upon receiving instruction from A’s bullpen coach Dan Hubbs to start warming up on Wednesday night, J.T. Ginn felt adrenaline come over him, unlike anything he’d ever experienced.

Called up from Triple-A Las Vegas the day before, Ginn had started 81 of his 82 games pitched over his last six seasons dating back to his freshman year at Mississippi State in 2019. He had little practice with pitching in relief, yet here he was set to make his Major League debut in the late innings of a close game.

“Unreal feeling, for sure,” Ginn said. “Definitely a little nervous. Excited. All those feelings. ... I don’t think I could feel my feet, honestly.”

Summoned in the top of the eighth inning with the A’s trailing the Rays by two runs, Ginn soaked in the moment as he jogged in from Oakland’s bullpen with his entrance music, “Solo” by Future, playing in the background as he took the Coliseum mound and prepared to make his Major League debut.

Despite his limited previous reliever experience, Ginn impressed in the role. The 25-year-old right-hander kept the A’s in an eventual 4-2 loss to Tampa Bay by turning in two scoreless innings. He retired six of his seven batters faced, three via strikeout, with his only baserunner reaching on a walk in the eighth.

"I threw the first warmup pitch where I wanted to,” Ginn said. “I kind of had a feeling it was going to be good after that. It ended up working out.”

Acquired from the Mets as part of the Chris Bassitt deal in March 2022, Ginn arrived with high expectations as he immediately slotted in on the A’s Top 30 Prospects list at No. 6 at the time. Since joining the A’s organization, however, Ginn has fallen down that list with more downs than ups as he’s battled struggles and injuries over the past couple of seasons.

Currently ranked outside of Oakland’s Top 30 Prospects list, Ginn received his first call to the Majors after a need arose in the bullpen following an injury to left-hander Scott Alexander. But while the opportunity is out of necessity, Ginn also earned it with his recent stretch of success. Over his last four starts with Las Vegas, Ginn pitched at least six innings each time out and allowed two earned runs or fewer in three of those four outings.

“I think just staying healthy and learning from those games I’ve pitched in has helped me get back to myself,” Ginn said. “It took being healthy for a season and getting out there and getting some innings.”

Ginn’s performance looked a lot like the pitcher the A’s were hoping for when they traded back in ‘22. He began by striking out three of his first four batters faced, all swinging, including a punchout of Junior Caminero -- rated the No. 2 overall prospect in baseball by MLB Pipeline -- on a 94.9 mph fastball.

Sent back out for the ninth, Ginn retired Jose Siri, Jonny DeLuca and Alex Jackson in order. The last two were retired on groundouts, which fit the scouting report. Among pitchers with at least 50 innings pitched in the Minors this season, Ginn’s 53.9% ground-ball rate ranked fifth-highest among all Minor League pitchers.

“I strike some people out, too,” Ginn said with a grin. “I had the strikeouts in the first inning. My second inning, I got the weak contact and ground balls like I normally do. I got to show a little bit of everything.”

Ginn’s outing certainly left a good first impression on A’s manager Mark Kotsay.

“That’s a great debut,” Kotsay said. “He pounded the zone. To strike out the side in the first inning of a big league debut is pretty impressive. I really liked his sinker, and the slider was a strikeout pitch. Really nice night. It was great to get him out there.”

On a night that saw the A’s drop back-to-back games for the first time since Aug. 3-4, the pitching was encouraging. Rookie starter Mitch Spence racked up a career-high 10 strikeouts through seven solid innings, with his only real mistake a costly go-ahead two-run homer surrendered to Jose Siri in the seventh.

“I got a lot more swing and miss and a lot of weak contact,” Spence said. “It really sucks that I hung that slider [to Siri] there at the end. But you just have to look at the positives.”