Mariners starting to hype a late 2025 draft find who defies comparison

The things the Mariners have a strong reputation for during the Jerry Dipoto era includes getting results with pitchers taken in the later rounds of drafts. Examples include Bryan Woo, who turned from a sixth-round pick into a Cy Young candidate and Logan Evans, a 12th round selection who last year became an invaluable depth starter. As such, fans shouldn't be surprised to hear some promising news regarding Lucas Kelly, a sixth-rounder who the team selected in last year's draft.

Kelly was previously a two-way player who admittedly doesn't have a whole lot of experience as a pitcher, but this doesn't takeaway from him being an promising prospect for the Mariners. What makes him stand out right away is his funky delivery — a hunched over and extreme wide release because of sidearm motion and setup on the third base side of the rubber:

Lucas Kelly is an imposing physical presence with a 99 mph fastball

Kelly's returns in college weren't exactly much to write home about, with him producing a 4.05 ERA and 1.425 WHIP last year in 21 relief appearances at Arizona State with the Sun Devils. However, with him finally focused solely on pitching, he missed a bunch of bats and recorded 34 strikeouts in 26.2 innings, which helped impress the Mariners enough to take him in the sixth round despite his limited experience on the mound.

The 22-year-old's four-seam fastball is his main weapon, with it reaching 99 mph during his college career and, as per Jim Callis of MLB.com, is up to 97 mph so far this spring. His other main weapon is a slider which tops out at 84 mph, for a pitcher who brings an imposing presence to the mound at 6-foot-4 and 220 pounds.

Kelly will now get the opportunity to show his stuff in the third annual edition of Major League Baseball's Spring Breakout schedule, which features 16 games between Mar. 19-22. The Mariners will face the Brewers this Friday afternoon at American Family Fields of Phoenix, with the righty being a legitimate contender to make an impact.

MLB Pipeline has Kelly ranked at 29 in their 2026 top 30 team prospects, and we appreciate you can never know how it's going to work out with relief pitching prospects. Doubters may even want to point at the small size he had last year in High-A Everett, when he allowed four hits, five walks and five earned runs in 6.0 combined innings.

However, the Palo Alto, California native then provided a glimpse of what he's capable of in the 2025 Northwest League championship series, striking out the Eugene Emeralds in the top of the ninth to record the save which clinched the third championship in AquaSox franchise history. Make no mistake that he has an intriguing profile and a ceiling which can conceivably see him develop into a high-leverage bullpen option at the Major League level in the long run.