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Seattle Mariners Promote Intriguing Pitching Prospect to Single-A Modesto

Originally posted on Minor League Baseball on SI
By Teren Kowatsch | Last updated Jun 27, 2025 6:21 PM ET

One of the most interesting pitching prospects in the Seattle Mariners farm system is moving up the minor leagues.

Chia-Shi Shen was promoted to the Single-A Modesto Nuts on Friday after seven outings with the organization's Arizona Complex League team.

In his first professional season stateside, the 21-year-old Taiwanese pitcher has posted a 1.93 ERA with 34 strikeouts in 28 innings across his seven appearances (three starts). He's allowed just seven runs (six earned) on 19 hits and has walked four batters. He's struck out five batters or more in four of his outings.

Mariners RHP Prospect Chia-Shi Shen has been promoted to Single-A Modesto

The 21 year-old had a 1.93 ERA and 34 K’s in 28 IP in ACL. Already has good feel of multiple pitches

pic.twitter.com/158AdCjusF
— Kick Dirt Baseball (@KickDirtBB) June 27, 2025

Shen was signed by Seattle as an international free agent on July 9, 2024. He is listed as the organization's No. 30 overall prospect, according to MLB Pipeline. The publication had the following scouting report on the right-hander:

All of Shen’s stuff does play up because he can throw all three offerings for strikes and knows how to miss bats by mixing his repertoire well and keeping hitters off-balance. His ceiling might be a bit limited, but his pitchability could help him move a bit more quickly and become a back-end starter in the big leagues.

Shen was originally supposed to be in the MLB system several years before the Mariners inked him to a contract. He initially came to terms with the Athletics on a $350,000 deal in 2022, but the contract fell through due to unknown reasons. Seattle took advantage and got into contact with Shen, but off-the-field issues forced him to remain in Taiwan.

Sehn, listed at 6-foot-3, 185 pounds, has plus-grade command that has led to success in his limited time in the farm system. Seattle and Shen will have a chance to see how that command and repertoire translates to "A" ball.

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

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