Reiver José SanmartÃÂn (born April 15, 1996) is a Colombian professional baseball pitcher for the San Francisco Giants of Major League Baseball (MLB). He has previously played in MLB for the Cincinnati Reds.
Sanmartin signed as an international free agent with the Texas Rangers on July 2, 2015. Sanmartin spent the 2016 and 2017 season with the DSL Rangers of the Rookie-level Dominican Summer League; going 0âÂÂ1 with a 5.23 ERA over innings in 2016, and 7âÂÂ1 with a 2.35 ERA and 56 strikeouts over innings in 2017. He split the 2017 season between the Spokane Indians of the Low-A Northwest League and the Hickory Crawdads of the Single-A South Atlantic League, going a combined 7âÂÂ2 with a 2.45 ERA and 56 strikeouts over 66 innings.
On November 20, 2017, Sanmartin was traded to the New York Yankees in exchange for Ronald Herrera. Sanmartin split the 2018 season between the Low-A Staten Island Yankees, the Single-A Charleston RiverDogs, the High-A Tampa Tarpons, and the Double-A Trenton Thunder. Between the four levels, he posted a combined 5âÂÂ7 record with a 2.81 ERA and 58 strikeouts over innings.
On January 21, 2019, Sanmartin and Sonny Gray were traded to the Cincinnati Reds in exchange for Shed Long Jr. and draft pick compensation. Sanmartin split the 2019 season between the High-A Daytona Tortugas, and the Double-A Chattanooga Lookouts, going a combined 4âÂÂ12 with a 4.05 ERA and 114 strikeouts over innings.
SanmartÃÂn did not play in a game in 2020 due to the cancellation of the Minor League Baseball season because of the COVID-19 pandemic. Sanmartin split the 2021 minor league season between Chattanooga and the Triple-A Louisville Bats, going a combined 10âÂÂ2 with a 3.32 ERA and 112 strikeouts over innings.
On September 27, 2021, Sanmartin's contract was selected to the active roster to make his MLB debut versus the Pittsburgh Pirates. In two starts in his rookie campaign, Sanmartin logged a pristine 1.54 ERA with 11 strikeouts in innings of work. Sanmartin spent the 2022 season mainly working out of the Reds' bullpen, making 45 appearances (4 starts) and registering a 4âÂÂ4 record and 6.32 ERA with 47 strikeouts in 57 innings pitched.
Sanmartin began the 2023 season working out of Cincinnati's bullpen as a situational reliever. In 14 games, he struggled to a 7.07 ERA with 13 strikeouts in 14 innings pitched. On May 7, he departed an appearance against the Chicago White Sox with what was described as left elbow soreness. He was placed on the 60-day injured list on May 14 with a stress reaction in his left elbow. On July 7, Sanmartin underwent seasonâÂÂending UCL surgery. He was non-tendered and became a free agent on November 17.
On November 19, 2023, SanmartÃÂn reâÂÂsigned with the Reds on a minor league contract. He spent the majority of 2024 with TripleâÂÂA Louisville, making 18 appearances and logging a 7.36 ERA with 18 strikeouts across innings pitched.
SanmartÃÂn began the 2025 season back with Louisville, where he compiled a 6-2 record and 2.75 ERA with 45 strikeouts across 42 appearances. On September 2, 2025, the Reds selected SanmartÃÂn's contract, adding him to their active roster. He made one scoreless appearance for Cincinnati, striking out two over innings pitched.
On November 6, 2025, SanmartÃÂn was claimed off waivers by the San Francisco Giants. On March 25, 2026, SanmartÃÂn was placed on the 60-day injured list due to a right hip flexor strain.