Rays' Top Prospect Theo Gillen Delivers Signature Moment in Double-A

He was just called up to Double-A last month

Sep 6, 2019; St. Petersburg, FL, USA; A detailed view of a Tampa Bay Rays hat and glove at Tropicana Field. Mandatory Credit: Kim Klement-USA TODAY Sports | IMAGN IMAGES via Reuters Connect

Friday was a big day for the Tampa Bay Rays organization. The Rays became the first American League team to reach 60 wins this year, and the franchise's top prospect showcased his flair for the dramatic with a game-winning hit.

Outfielder Theo Gillen, MLB Pipeline's No. 9 overall prospect for 2026, went 2-for-3 at the plate with two walks, three RBIs, and three runs scored for the Double-A Montgomery Biscuits on Friday. But most importantly, the 20-year-old drilled a walk-off solo shot in the bottom of the ninth to give Montgomery a 9-8 victory over the Birmingham Barons, the Double-A affiliate of the Chicago White Sox. The lefty-swinging outfielder crushed a line drive to right field that left the yard in a hurry to send the Biscuits home with a win.

Gillen was promoted to Double-A toward the end of June, so he's still in the early days of his time with Montgomery. But this recent performance and clutch hit are good signs of the young prospect's promising potential that's been on display all season.

Theo Gillen is just getting started at Double-A

Jul 14, 2024; Ft. Worth, TX, USA; Theo Gillen is drafted by the Tampa Bay Rays with the 18th pick during the first round of the MLB Draft at Cowtown Coliseum. Mandatory Credit: Kevin Jairaj-USA TODAY Sports | USA TODAY Sports via Reuters Connect

After being selected with the 18th-overall pick in the 2024 MLB Draft, Gillen has rapidly ascended to the top of Tampa Bay's farm system. It likely won't be long until he's joined by the Rays' 2026 first-round pick, high school shortstop Grady Emerson, as the most highly touted prospects in the organization.

So far this year, Gillen has posted a .321 batting average, a .427 on-base percentage, and a .990 OPS with 16 homers, 66 RBIs, and 36 stolen bases in 78 games across two minor league levels. The 20-year-old began the season with the High-A Bowling Green Hot Rods, where he hit .342 with 12 home runs, 44 RBIs, and 28 stolen bases in 57 games. And now, in his first 21 Double-A games, the young outfielder has a .265 batting average with four homers and 22 RBIs.

Since this is Gillen's first taste of Double-A action, he'll most likely finish the 2026 campaign at that level. But if he starts to heat up at the plate over the next few weeks, it'd be interesting to see if the Rays will consider having their top prospect make his Triple-A debut this year.