Although it may be hard to tell with the unseasonably warm weather this winter in the Mile High City, spring is in the air and on the horizon. Pitchers and catchers reported to the Rockies’ complex in Scottsdale, Arizona last week, with position players reporting yesterday. The first game of spring training is this coming Friday, and the 2026 season of Major League Baseball will be here before we know it.
The new-look Colorado Rockies front office and coaching staff have emphasized competition and the earning of positions over the off-season. They’ve brought in plenty of players who could complete for virtually every position—save for center field, catcher, and shortstop—and the prospects and youngest Rockies will have to earn their way into starting roles.
However, that doesn’t mean prospects won’t be given a chance to show their stuff.
A sizeable handful of prospects—many of them listed in our PuRPs rankings—received non-roster invites to camp this year to showcase how they might be part of this organization’s future. We’ll start by looking at the young pitchers.
Konnor Eaton (No. 28 PuRP, Pre-Season 2026) and Sean Sullivan No. 8 PuRP, Pre-Season 2026) are the two southpaw prospects with non-roster invites this spring.
Eaton, 23, was the Rockies’ sixth round pick out of George Mason University in the 2024 draft. In his professional debut season, he pitched just 11 innings, all of which were out of the bullpen. However, his workload both in college and in 2025 are that of a starter.
Eaton made 23 starts with the High-A Spokane Indians last season with a solid 3.56 ERA over 121 1/3 innings and struck out 125 batters before a late season promotion to Double-A Hartford. With the Yard Goats he made another four starts over 18 2/3 innings and posted a 5.30 ERA with 24 strikeouts. While with Spokane, he earned Northwest League Pitcher of the Week in late June after pitching back-to-back Quality Starts with 11 strikeouts in each game.
The 6’3” lefty is most likely to return to Hartford to start the 2026 season, but his ability to strike out batters and limit walks throughout his minor league career so far show promise. He misses bats with a low-to-mid 90s fastball and a high-spin sweeping slider with late horizontal break. He also has a changeup in development.
Sullivan, 23, had his 2025 season delayed after having off-season hip surgery. When he made it to Double-A Hartford in mid-May, he hit the ground running with a stupendous season.
The 2023 second round pick out of Wake Forest made 18 starts for the Yard Goats, posting a 3.14 ERA over 97 1/3 innings of work and 95 strikeouts to 24 walks. Sullivan did seem to run out of gas at the end of the season. In his final four starts, he pitched more than four innings just once and had a combined ten strikeouts over 16 2/3 innings. He had previously been on a streak of tallying five or more strikeouts in 11 of his last 12 starts.
With no experience over Double-A, Sullivan will likely start his 2026 campaign with the Triple-A Albuquerque Isotopes. However, he is virtually a lock to make his Major League debut at some point this year.
With Gabriel Hughes (No. 12 PuRP, Pre-Season 2026) now on the 40-man roster to protect him from this off-season’s Rule 5 draft, the right-handed pitching prospects left with non-roster invites fly a bit under the radar.
25-year-old reliever Brayan Castillo started his 2025 season with Double-A Hartford and was a reliable strikeout machine out of the Yard Goats’ bullpen. In 26 appearances, he struck out 40 batters, walked 17, and gave up only one home run on his way to a 2.12 ERA over 34 innings.
Castillo was promoted to Triple-A Albuquerque, where his debut was less than stellar. In his first Pacific Coast League game against the Reno Aces, he yielded five earned runs on four hits—including a home run—with a walk and a strikeout over 2/3 of an inning. However, he was lights out for the rest of the season. Castillo gave up earned runs in just two of his final 14 appearances and struck out 23 batters over 17 1/3 innings.
Also headed to Rockies camp is Eiberson Castellano, a 24-year-old from Venezuela who originally hails from the Philadelphia Phillies system. Castellano was selected by the Minnesota Twins in last year’s Rule 5 draft, but was returned to the Phillies after failing to make the Opening Day roster in spring training. He was allowed to become a minor league free agent at the end of the season.
What makes Castellano intriguing is his young age and the fact that he’s not far removed from a strong 2024 campaign. In 22 appearances—including 20 starts—across the High-A Jersey Shore BlueClaws and Double-A Reading Fightin’ Phils, Castellano posted a 3.99 ERA with 136 strikeouts and 29 walks over 103 2/3 innings. He was named the Phillies organization’s best minor league pitcher for his efforts.
Castellano struggled in 2025 pitching mostly for Double-A Reading. Battling both injuries and his own command, he carried a 5.14 ERA in 20 appearances and only made one start. While he did strike out 39 batters in 36 1/3 innings, he also walked 17 and carried a bloated 9.5 hits per nine innings.
A healthy Castellano then attended the Arizona Fall League with the Surprise Saguaros and made a solid four starts, striking out 18 batters with a 3.86 ERA over 14 innings.
Castellano can work both as a starter or from the bullpen and has done both extensively in his young professional career. His lively four-seam fastball rises late and can hit up to 98 MPH, and his excellent low-80s curveball featured a whopping 49% whiff rate in 2024. He also has a promising changeup.
With a full 40-man roster, multiple veteran signings in Jose Quintana, Tomoyuki Sugano, and Michael Lorenzen brought in over the off-season, and Rule 5 protections like Gabriel Hughes and Welinton Herrera on the inside track, it’s difficult to see a path where any of the non-roster invite pitchers make the Opening Day roster.
However, with a long season ahead and the Rockies looking to evaluate talent and establish a new floor, strong performances this spring could indicate who goes where for minor league assignments and who might be on the short list for an eventual call-up.
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