Santos begins his third season with the Ducks and 13th in professional baseball. The right-hander combined to make 64 appearances during his first two seasons with the Flock (2024-25), compiling a 10-2 record with a 0.55 ERA and 20 saves. In 65.2 innings of work, he allowed just 10 runs (four earned) on 32 hits and 32 walks while striking out 113 batters (15.5 strikeouts-per-nine-innings). The 31-year-old was voted by Ducks fans as the 2024 Team MVP, presented by Delmonte-Smelson Jewelers, after finishing third in the Atlantic League with 14 saves and leading all Ducks pitchers with 45 appearances to go along with a 6-1 record and a 0.58 ERA.

The Dominican Republic native began the 2025 season in the Mexican League with Leones de Yucatan and Rieleros de Aguascalientes, combining to pitch in 13 games. Prior to joining Long Island, he spent nine seasons in the St. Louis Cardinals organization (2012-19, 2021) and one in the Washington Nationals system (2022), reaching as high as Triple-A. In 214 games (46 starts) during that span, he accrued a 24-31 record with a 3.86 ERA, 12 saves and 458 strikeouts to 215 walks over 492.1 innings. Santos was originally signed by the Cardinals as an international free agent in 2012.