MESA, Ariz. -- Amidst a roller-coaster season, J.T. Ginn appears to have found his level during the Arizona Fall League. The right-hander spun four scoreless frames and struck out a quartet for the Solar Sox in Friday’s 3-0 loss to the Scorpions at Sloan Park, marking his first time as a member of the A’s organization that he worked at least four frames and kept the opposition off the scoreboard.

“He was phenomenal,” Mesa manager Bobby Crosby said. “His stuff was diving; he’s got a heavy sinker, worked on the cutter a little bit and his changeup’s great.”

Aside from a first-inning walk where his command momentarily slipped, Ginn, the A's No. 9 prospect, peppered the zone his first time through the order. His lone base hit allowed was a chopper through the right side in the fourth, but catcher Blake Hunt quickly squelched any whispers of a threat by cutting down the runner as he attempted to advance on a pitch in the dirt.

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“Definitely wanted to get the sinker and the changeup going, especially to right-handed hitters,” said Hunt, who caught Ginn for the first time. “[Ginn] said that plays really well, and obviously it did. A lot of soft contact early and he was getting quick outs.”

Four of the first six outs logged by Ginn came via the groundout. That’s no accident, as the 23-year-old posted a 61.6% ground-ball rate during his first season of pro ball in 2021, the second-highest mark in the Minors for all hurlers who accrued at least 90 innings. His sinker -- which sat in the low-90s -- was deployed early and often Friday.

A forearm ailment sidelined Ginn for more than two months during the summer, making him a prime AFL candidate as he looks to continue bumping up his workload. Over four starts with the Solar Sox, Ginn has allowed just three runs over 12 frames (2.25 ERA).

“His confidence is building,” said Crosby, who managed Ginn this season with Double-A Midland. “I mean, he’s always had good stuff. But it seems like he’s maturing a little bit, he’s placing the ball where he wants to. During the year, he was good, but it was kind of weird -- when he’d get hit around, you go, ‘How is this possible?’”

While the 6.11 ERA that Ginn posted over 10 starts at Midland may jump off the page, a deeper dive into the numbers shows that a limited sample size and some unfortunate luck skewed that mark. His line-drive percentage only incrementally rose from 2021 (when he had a 3.03 ERA), while his BABIP skyrocketed to .350; his xFIP also sat just higher (4.10) from his stints with Single-A St. Lucie (3.78) and High-A Brooklyn (3.90) while in the Mets organization.

Oakland made a point to acquire Ginn, a second-round pick in the 2020 Draft out of Mississippi State, when dealing Chris Bassitt to the Mets in March. His sinker-heavy, control-first arsenal has definite benefits, although it remains to be seen if he can hone that style over the course of a full campaign at the upper levels. Also up for grabs is whether the new shift rules coming to the big leagues in 2023 -- which will pit two fielders on the infield dirt on either side of second base -- adversely affects pitchers with a similar style.

Ginn is the highest-ranked A's arm on the Mesa club, as Oakland sent Top 30 arms to the desert in an impressive bunch with Ryan Cusick (No. 13), Mason Miller (No. 20) and Colin Peluse (No. 24) also in tow.

“It’s exciting,” Crosby said of the organization’s young talent on the hill. “We made some trades this year, so to have these arms and guys [whose] arms are live, it’s kind of just about them growing and learning how to pitch and learning how to spot up a little bit better. So far, the guys that have been here have done an awesome job.”