Rockies to promote Sean Sullivan for Major League debut

SCOTTSDALE, ARIZONA - MARCH 12: Sean Sullivan #85 of the Colorado Rockies pitches during the the second inning of a spring training game against the Arizona Diamondbacks at Salt River Fields at Talking Stick on March 12, 2026 in Scottsdale, Arizona. (Photo by John E. Moore III/Getty Images) | Getty

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What is the story about?

The Colorado Rockies are reportedly promoting left-handed pitcher Sean Sullivan (No. 8 PuRP) to start Friday night’s game against the Athletics. The Gazette’s Kevin Henry was among the first to report on the news. The Rockies have yet to officially announce the move.

Sullivan was the Rockies’

second-round pick in the 2023 draft after pitching 69.2 innings with a 2.45 ERA in his final season with Wake Forest. His fastball typically sits in the high 80’s and he relies on a mixture of good command and deception from a low arm slot to get batters out.

Making stops at every Rockies full-season minor league affiliate, Sullivan continued to have great results until hitting a roadblock in the hitter-friendly PCL this season.

In 2024, across stops at both High-A and Double-A, Sullivan pitched 115.1 innings with a 2.11 ERA and earned the High-A Northwest League Pitcher of the Year award. He followed that up with a full season at Double-A Hartford in 2025, where, across 97.1 innings, he recorded a 3.14 ERA backed up by a 3.17 FIP and a sterling 1.09 WHIP.

Upon reaching Triple-A Albuquerque to start this season, however, some of the warning signs in his profile began to shine through. In eleven starts for the Isotopes, Sullivan sports a 5.60 ERA backed up by a 5.70 FIP. Most notably, he has not been able to control the long ball nearly as well as he had in the lower minors, and his HR/9 has jumped from 0.61 last year to 1.65 so far this season.

He will get his first major league start in a familiar stadium, as tonight’s game against the Athletics will be hosted in the Triple-A Las Vegas stadium, where Sullivan last pitched on May 19th. In that start, he lasted 4.2 innings and allowed six earned runs on twelve hits while striking out four and allowing no walks.