P | Bats/Throws: L/L | 6' 0" 166 lbs | Age: 22
MLB Pipeline Rank
Rockies: No. 14
W L ERA G GS SV IP SO WHIP
2026 0 1 13.50 2 0 0 2 4 3.50
Career Minors 25 11 3.36 159 1 21 216.2 313 1.20
G W-L ERA IP SO WHIP
2026 2 0-1 13.50 2 4 3.50
Career Minors 159 25-11 3.36 216.2 313 1.20
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Standard Minor League Pitching Statistics

SeasonTmLGLWLERAGGSSVIPHRERHRBBSOWHIP
2021 DSL Colorado DSL ROK 2 0 5.16 18 0 1 22.2 17 14 13 1 11 28 1.24
2022 DSL Rockies DSL ROK 5 1 2.93 20 1 2 43.0 33 19 14 0 14 54 1.09
2023 ACL Rockies ACL ROK 2 0 3.27 21 0 1 22.0 16 8 8 0 15 36 1.41
2024 2 Teams Minors 11 4 3.47 46 0 0 62.1 51 25 24 2 23 92 1.19
2024 Fresno Grizzlies CAL A 8 2 2.38 23 0 0 34.0 25 9 9 1 9 62 1.00
2024 Spokane Indians NWL A+ 3 2 4.76 23 0 0 28.1 26 16 15 1 14 30 1.41
2025 2 Teams Minors 5 5 2.64 52 0 17 64.2 49 23 19 2 25 99 1.14
2025 Spokane Indians NWL A+ 1 0 0.49 15 0 10 18.1 8 1 1 0 6 29 0.76
2025 Hartford Yard Goats EAS AA 4 5 3.50 37 0 7 46.1 41 22 18 2 19 70 1.29
2026 Albuquerque Isotopes PCL AAA 0 1 13.50 2 0 0 2.0 5 3 3 0 2 4 3.50
Albuquerque Isotopes PCL AAA 0 1 13.50 2 0 0 2.0 5 3 3 0 2 4 3.50
Hartford Yard Goats EAS AA 4 5 3.50 37 0 7 46.1 41 22 18 2 19 70 1.29
Spokane Indians NWL A+ 4 2 3.09 38 0 10 46.2 34 17 16 1 20 59 1.16
Fresno Grizzlies CAL A 8 2 2.38 23 0 0 34.0 25 9 9 1 9 62 1.00

Scouting Report

2026

Scouting grades: Fastball: 60 | Slider: 60 | Changeup: 40 | Control: 45 | Overall: 45

It’s not often that a pitcher enters pro ball via the international free agent market and pitches only in relief. That’s what Herrera has done since signing with the Rockies for $200,000 in January 2021. The Rockies have allowed the left-handed to develop slowly, and he spent two years in the Dominican Summer League and one in the Arizona Complex League, finally reaching full-season ball in 2024. After pitching well in the Dominican Winter League, things clicked more in 2025 when he reached Double-A for the first time, represented the organization in the Futures Game and pitched in the Arizona Fall League, all en route to be added to the 40-man roster in the offseason.

When you combine a funky delivery with velocity, you might get a very valuable left-handed reliever. Herrera cranked his fastball up to 99 mph in 2025, averaging around 95 and he throws it from a low three-quarters slot that allows it to carry above barrels, resulting in a lot of misses and chases. He leans on the heater, sometimes too much, and will have to keep using his slider more, because it has the chance to really have teeth. He threw it around 86 mph across all stops last year with depth to it when he finishes it and it missed bats at a 44-percent rate, according to Synergy. He actually has an upper-80s changeup that could be useful against right-handed hitters, but it’s not as consistent.

Herrera will pitch all of 2026 at age 22 and the next step in his development is to learn things like holding runners and fielding his position. He’s on the roster now, and especially if that slider starts showing up as a true out pitch, he could be a high-leverage reliever in the big leagues.


2025

Scouting grades: Fastball: 60 | Slider: 50 | Changeup: 40 | Control: 45 | Overall: 40

Teams interested in signing young amateur pitchers tend to look for clean deliveries and arm actions, guys who look like future starters. Perhaps that’s why some teams didn’t consider Herrera when the 2021 international signing period opened. The Rockies were willing to think outside the box and bring the smallish lefty with the funky mechanics into the organization; initial progress was slow. Herrera spent two years in the Dominican Summer League and one in the Arizona Complex League, but he started taking off in 2024, pitching his way from Single-A Fresno to High-A Spokane, where he finished things off with three perfect innings during the team’s championship run. He tacked on 10 strong appearances in the Dominican Winter League.

Used only as a reliever, Herrera relies largely on his fastball-slider combination to go right after hitters. His fastball sits around 95 mph and touches 97 and it comes from a low three-quarters arm slot, an upshoot heater that has carry above the barrel that gets a lot of swing-and-miss. He can get too fastball-reliant and will have to keep learning to trust his 84 mph slider. It's a pitch he has improved by more consistently staying on top of; it flashes better than average while dropping below barrels. He actually has feel for a changeup with depth, but he doesn’t throw it much.

Herrera pounded the strike zone during his time with Fresno, but he wasn’t as sharp with Spokane. He’s made adjustments before, so there’s confidence he’ll be able to become another legitimate big league bullpen piece for the Rockies. 



Awards




Transactions

Team Date Transaction
03/08/2026 Colorado Rockies optioned LHP Welinton Herrera to Albuquerque Isotopes.
03/05/2026 LHP Welinton Herrera assigned to Colorado Rockies Prospects.
11/18/2025 Colorado Rockies selected the contract of LHP Welinton Herrera from Hartford Yard Goats.
09/10/2025 LHP Welinton Herrera assigned to Salt River Rafters.
07/14/2025 Hartford Yard Goats activated LHP Welinton Herrera.
07/11/2025 Hartford Yard Goats placed LHP Welinton Herrera on the temporarily inactive list.
07/11/2025 LHP Welinton Herrera assigned to National League Futures.
05/20/2025 LHP Welinton Herrera assigned to Hartford Yard Goats from Spokane Indians.
03/12/2025 LHP Welinton Herrera assigned to Colorado Rockies.
03/06/2025 activated LHP Welinton Herrera.
10/20/2024 LHP Welinton Herrera assigned to Aguilas Cibaenas.
10/20/2024 Aguilas Cibaenas activated LHP Welinton Herrera.
06/27/2024 LHP Welinton Herrera assigned to Spokane Indians from Fresno Grizzlies.
04/02/2024 LHP Welinton Herrera assigned to Fresno Grizzlies from ACL Rockies.
06/04/2023 LHP Welinton Herrera assigned to ACL Rockies.
06/03/2022 LHP Welinton Herrera assigned to DSL Rockies from DSL Colorado.
06/03/2022 DSL Rockies activated LHP Welinton Herrera.
07/09/2021 LHP Welinton Herrera assigned to DSL Colorado.
01/20/2021 Colorado Rockies signed free agent P Welinton Herrera.