A Seattle Mariners Armed Forces Day hat is pictured in the dugout before a game against the Atlanta Braves on May 20, 2023, at Truist Park. Brett Davis-Imagn Images

Seattle Mariners Top 100 Prospect Makes High-A Debut For Everett AquaSox

Originally posted on Minor League Baseball on SI
By Teren Kowatsch | Last updated Aug 17, 2025 12:15 PM ET

One of the Seattle Mariners most impressive (and youngest) prospects made his first appearance for the High-A Everett AquaSox against the Hilsboro Hops on Saturday.

Right-handed starting pitcher Ryan Sloan made his first High-A start in the AquaSox's 3-2 loss to the Hops.

The 19-year-old hurler made a solid first impression. He threw four innings in his debut for Everett. He finished with two strikeouts and allowed one earned run on four hits. He threw 52 pitches, including 42 strikes, and didn't allow a run until the final inning of his outing. The first 17 pitches he threw were strikes.

First HiA strikeout for Ryan Sloan. pic.twitter.com/exNxwreScn
— Mariners Minors (@MiLBMariners) August 17, 2025

Sloan (No. 42 MLB Pipeline top 100, No. 67 Baseball America top 100) was selected by Seattle in the second round of the 2024 MLB Draft out of high school. He was considered one of the best prep pitching prospects in the class and already possessed a major league frame (6-foot-5, 220 pounds).

Sloan made his pro debut this season with the Single-A Modesto Nuts. He made 18 starts before being promoted to the AquaSox on Aug. 10.

While with Modesto, Sloan posted a 3.44 ERA with 77 strikeouts in 70.2 innings pitched. He allowed an opposing batting average of .249 and just two home runs.

Ryan Sloan on the mound pic.twitter.com/ClHOV2lFtL
— Mariners Player Development (@MsPlayerDev) July 3, 2025

Including his debut with Everett, Sloan has a 3.38 ERA this season with 79 strikeouts in 74.2 innings pitched across 19 starts.

Sloan is one of three pitchers drafted by the Mariners in the last two draft classes who are in the top 100. Switch-pitcher Jurrangelo Cijntje (No. 95 MLB Pipeline top 100, No. 92 Baseball America top 100) was picked in the first round of the 2024 draft, made his pro debut this season with Everett, and was promoted to the Double-A Arkansas Travelers on Aug. 4.

Final line for Jurrangelo Cijntje: 3IP, 2H, 3R, 2ER, 4BB, 4K, HBP, 78-41. Just one of those days when he had to fight his control. pic.twitter.com/pThxRB6vZ1
— Mariners Minors (@MiLBMariners) August 17, 2025

Left-handed pitcher Kade Anderson (No. 22 MLB Pipeline top 100, No. 31 Baseball America top 100) was drafted by the Mariners with the No. 3 overall pick in this year's draft. He'll make his pro debut in 2026.

Kade Anderson, 95mph Fastball & 83mph Breaking Ball, Overlay pic.twitter.com/LiFuFPvTXm
— Rob Friedman (@PitchingNinja) June 15, 2025

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This article first appeared on Minor League Baseball on SI and was syndicated with permission.

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