Scouting Report
Updated May 20, 2026
Yilber Diaz is a minor league pitcher (RHP, No. 21 prospect) with the Arizona Diamondbacks organization. In April 2026, he was named minor league pitcher of the month after an outstanding performance with the Aces (Triple-A). He allowed no runs in 9 of his 10 appearances with a 0.66 ERA, ranking second among all Triple-A relievers. Diaz features the fastest average fastball velocity (95.3 MPH) among prospect comparables and has improved his strike zone control significantly in 2026, decreasing his walk rate substantially from spring training. Despite previous struggles and uncertainty about his future, Diaz has worked exceptionally hard to prepare for his opportunity. He would be a strong addition to the Diamondbacks bullpen.
Strengths
- + Exceptional April performance with 0.66 ERA in Triple-A
- + Allowed no runs in 9 of 10 appearances
- + Second-best ERA among all Triple-A relievers in April
- + Fastest average fastball velocity at 95.3 MPH
- + Significant improvement in strike zone control and walk rate in 2026
- + Named minor league pitcher of the month for April
- + Strong work ethic and determination despite previous setbacks
- + Potential to be valuable addition to MLB bullpen
Weaknesses
- - Previous struggles and uncertain career path
- - Limited barrel usage noted in player review
- - High walk rate in spring training 2026
- - Still in minor leagues and not yet promoted to MLB
- - Needs to continue proving consistency at higher levels
Injury Status: IL-60
About
Yilber Diaz is a sp for the Arizona Diamondbacks.
Player Overview
SP
Arizona Diamondbacks