Colorado Rockies prospect Welinton Herrera is looking for a Spring Training invite. If he continues to pitch well in the AFL (AZ Fall League), he just may get it. With the Rockies bringing in a new General Manager and Field Manager, Herrera is showcasing his talent for a spot on the big-league club.

Used as a Bullpen Arm

Since signing at age 17 in 2021, Herrera has started only one game. He has, however, appeared in 157 games as a bullpen arm in MiLB. This past season, he was primarily used as a closer for both Single-A Spokane and Double-A Hartford. The left-hander, with a rhythmic approach to his pitching style, combined for 17 saves and 99 strikeouts in 64.2 innings.

Invited to the AFL

The Rockies added him to the AFL roster so he could continue to work on his game. They want him to work on his pitch selection because he can become too reliant on his fastball, which leads to inconsistency. Working on his overall confidence on the mound is another aspect of his game that needs improvement. The AFL affords him the chance to work on all aspects of his game in real-world play against players he will most likely play against in MLB.

Responded Well

Colorado Rockies prospect Welinton Herrera has responded well so far in his AFL play. His fastball has been around 95 mph. His slider is working on both left- and right-handed AFL hitters. In five relief appearances, he’s holding a 1.50 ERA. He has faced 28 batters with nine strikeouts and only four hits allowed over six innings.

Top 30 Rockies Prospects

According to MLB prospect rankings, Herrera is the number 19 prospect for the Rockies. He made his name known at the Spring Breakout game against Chicago White Sox prospects in March 2025. He had a positive showing and won the game. Later on in the season he played in the 2025 Futures Game. Herrera picked up the save by recording the final out of the game.

40-Man Roster

Herrera is considered the Rockies’ top reliever prospect in their system, according to the scouts. With his pitching performance in the AFL looking good, he has an opportunity to be a 40-man roster candidate. The Rockies are going to have a new set of bullpen arms for next season. If on the 40-man roster, Herrera will get plenty of chances in Spring Training to demonstrate the skills he can bring to the big-league team and earn his spot.

Outlook

At this point, the Rockies are a few years away from being competitive. With a top-notch reliever and a possible future closer in Herrera, there is a bright outlook for this organization—and for Herrera.

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