A detailed view of a Colorado Rockies hat and glove on the bench against the Atlanta Braves in the ninth inning at Truist Park. Brett Davis-Imagn Images

Rockies Prospect Trio Make Huge Impression in Arizona Instructional League

Originally posted on Colorado Rockies on SI
By Matt Postins | Last updated Oct 4, 2025 10:00 AM ET

The Colorado Rockies made their draft selections in July. But not all those players made their professional debuts with minor league affiliates.

For many of those players, they end up in instructional league in Arizona, which happens shortly after the Arizona Complex League season ends. The instructional league, for many young players, are their first professional appearances against other young pros.

The Colorado Rockies sent a contingent of players to the instructional league and recently Baseball America spotlighted 10 pitchers that put themselves on the radar of not only the Rockies but all of baseball. Colorado had three players on the list — Yujanyer Herrera, Antoine Jean and Riley Kelly.

A Rockies Pitching Trio

Rick Osentoski-Imagn Images

Herrera is a name that some Rockies prospect watches likely know. He is a Top 30 prospect in the system, ranked No. 17 per MLB Pipeline. The 22-year-old has only reached High-A Spokane, but he had an excuse. He missed the season recovering from Tommy John surgery. The Venezuelan had the surgery in September of 2024, and the instructional league was his first chance to face live hitting in a game environment.

Baseball America reviewed his play and found that his fastball and sinker were consistently in the 94-96 mph range and that he built up to working multiple innings, which should set him up to work as a starter in 2026.

Jean, a left-hander, was drafted in the seventh round of the 2025 MLB draft out of Houston but wasn’t assigned to an affiliate. So, his work in the instructional league was his first against professional hitters.

Baseball America profiled him as a pitcher with an over-the-top release on his fastball and a classic 12-6 breaking pitch. He was the Big 12 pitcher of the year in 2025 and could be assigned to either Spokane or even Double-A New Hampshire next season, depending on his progress.

He was a reliever in college and was second nationally in strikeouts per nine innings pitched (14.78) and hits allowed per nine innings pitched (5.37). That projects him as a high-leverage set-up man or even a closer.

Kelly, a right-hander, was another draft pick in July, selected in the fourth round out of UC Irvine. There, he went 4-1 with a 3.78 ERA in 17 games (12 starts), with 70 strikeouts and 32 walks in 66.2 innings.

Kelly didn’t pitch in the minors this year. The Rockies used him as a starter in instructional league, and he logged multiple innings. Baseball America indicated that Kelly did have some command issues. But he logged a fastball that consistently hit 94 mph, and the idea is to help him add more velocity.

This article first appeared on Colorado Rockies on SI and was syndicated with permission.

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