Gregory Santos

Gregory Omar Santos Bio

Gregory Omar Santos (born August 28, 1999) is a Dominican professional baseball pitcher currently in the San Francisco Giants organization. He has played in Major League Baseball (MLB) for the San Francisco Giants, Chicago White Sox, and Seattle Mariners since making his debut in 2021. Santos signed with the Boston Red Sox as an international free agent in 2015 and has developed through various minor league levels throughout his career. He is known as a right-handed relief pitcher who has appeared in 79 major league games across five seasons.

Early Life and Background

Santos was born on August 28, 1999, in the Dominican Republic. Specific details about his childhood, family background, and early education are not widely available in public sources. Like many Dominican players, Santos grew up in a baseball culture where the sport serves as a pathway to professional opportunities. He showed promise as a pitcher from an early age, catching the attention of Major League Baseball scouts operating in the Dominican Republic.

Santos pursued baseball professionally and was signed by an MLB team as an international free agent, following a common development path for Dominican players. His journey illustrates the significant role that Dominican Republic plays in supplying talent to American professional baseball, particularly through the international signing system.

Path to Professional Baseball

Santos signed with the Boston Red Sox as an international free agent on August 28, 2015, for $275,000 on his 16th birthday. He began his professional career in 2016 with the Dominican Summer League Red Sox. In his debut season, he went 3-3 with a 4.17 earned run average and recorded 25 strikeouts over 41 innings pitched. His early performance demonstrated potential as a developing pitcher in the Red Sox farm system.

In 2017, Santos made eight starts for the DSL Red Sox, posting an impressive 2-0 record with a 0.89 ERA and 24 strikeouts across 30 and one-third innings. His dominant performance in limited action highlighted his effectiveness as a starter in the early stages of his career. On July 26, 2017, Santos and Shaun Anderson were traded to the San Francisco Giants in exchange for infielder Eduardo Nunez, marking a significant change in his organizational affiliation. After the trade, he split the remainder of the 2017 season between the DSL Red Sox and Dominican Summer League Giants, going a combined 3-0 with a 1.29 ERA and 41 strikeouts over 49 innings.

Gregory Omar Santos Career

Minor League Development (2017-2020)

Following the trade to the Giants organization, Santos continued his development in the minor leagues. In 2018, he played for the Salem-Keizer Volcanoes in the Northwest League, where he posted a 2-5 record with a 4.53 ERA over 49 and two-thirds innings. His performance earned him recognition as a Northwest League mid-season All-Star, indicating his progress as a professional pitcher. The following season, 2019, Santos played for the Augusta GreenJackets, going 1-5 with a 2.86 ERA over 34 and two-thirds innings.

Unfortunately, Santos missed the second half of the 2019 season due to shoulder issues, representing an early setback in his career trajectory. He did not play in 2020 because the minor league season was canceled due to the COVID-19 pandemic. Despite the lost season, the Giants added Santos to their 40-man roster on November 20, 2020, to protect him from the Rule 5 draft. This move demonstrated the organization’s commitment to his development and belief in his potential.

San Francisco Giants Breakthrough (2021-2022)

Santos received his first major league call-up on April 22, 2021, when the Giants promoted him to the major leagues. He made his MLB debut that day against the Miami Marlins, pitching a scoreless inning of relief. In that debut appearance, he recorded his first two major league strikeouts, punching out Magneuris Sierra and Jazz Chisholm Jr. At the time of his debut, Santos was the sixth-youngest player in the National League. He was optioned to the Giants’ alternate site in Sacramento on April 28 to make room for new outfielder Mike Tauchman and began his minor league season with the Triple-A Sacramento River Cats.

However, Santos’ 2021 season was interrupted when he was suspended 80 games after testing positive for the banned androgen and anabolic steroid Stanozolol. Following the suspension, he played for the Scottsdale Scorpions in the Arizona Fall League, where he went 0-1 with a 4.15 ERA in 10 relief appearances. His performance earned him recognition as an Arizona Fall League Rising Star. In 2022, Santos split time between the Giants’ Triple-A affiliate Sacramento and the ACL Giants Black, posting a combined 1-2 record with one save and a 4.63 ERA in 35 games. He made two relief appearances for the major league club that season, allowing three hits, three walks, and two strikeouts in 3.2 innings. On December 19, 2022, Santos was designated for assignment following the signing of Sean Manaea.

Chicago White Sox (2023)

On December 22, 2022, Santos was traded to the Chicago White Sox in exchange for minor league pitcher Kade McClure. The trade provided Santos with a fresh start in a new organization. In 2023, he appeared in 60 relief games for Chicago, recording a 3.39 ERA with 66 strikeouts and five saves across 66 and one-third innings pitched. His performance represented his most productive major league season to that point, establishing him as a reliable option in the White Sox bullpen. The 60 appearances demonstrated his durability and ability to contribute consistently at the major league level.

Seattle Mariners (2024-2025)

On February 3, 2024, the White Sox traded Santos to the Seattle Mariners in exchange for right-handed pitcher Prelander Berroa, outfielder Zach DeLoach, and a Round B Competitive Balance draft pick. His tenure with Seattle began with injury concerns as he started the year on the injured list with a right lat strain. He was transferred to the 60-day injured list on April 25 before being activated on July 8. In eight appearances for Seattle, Santos recorded a 4.91 ERA with six strikeouts across 7.1 innings pitched.

The 2025 season proved challenging for Santos. He made another eight appearances for the Mariners, compiling a 1-1 record and 5.14 ERA with no strikeouts over seven innings of work. On April 25, 2025, Santos was placed on the 15-day injured list due to right knee inflammation. It was announced that he would require cleanup surgery to repair cartilage in his knee. He was transferred to the 60-day injured list on April 29. On November 21, Santos was non-tendered by Seattle and became a free agent, ending his two-year tenure with the Mariners.

San Francisco Giants Return (2026-Present)

On December 17, 2025, Santos signed a minor league contract with the San Francisco Giants, returning to the organization where he first reached the major leagues. He was assigned to the Triple-A Sacramento River Cats to begin the regular season. With Sacramento, he recorded a 2.45 ERA with six strikeouts and three saves over eight appearances, demonstrating his ability to perform at the Triple-A level. On April 29, 2026, the Giants selected Santos’ contract, adding him to their active roster and giving him another opportunity at the major league level.

Pitching Style and Strengths

Santos operates primarily as a right-handed relief pitcher. His career has seen him work extensively as a bullpen arm, filling various roles including setup duties and closing opportunities. His minor league track record shows versatility between starting and relieving, with varying results across different levels. His strikeout numbers at the major league level indicate the ability to miss bats, though his ERA figures suggest room for continued development in command and consistency.

Notable Events and Milestones

Several significant moments define Santos’ career trajectory. His MLB debut on April 22, 2021, marked the culmination of years of minor league development, where he immediately showcased his stuff by recording two strikeouts in his first appearance. His suspension in 2021 represented a notable setback that interrupted his rookie season. The five-save performance with the White Sox in 2023 demonstrated his capability in high-leverage situations. His career win-loss record stands at 3-6 with a 4.14 ERA and 78 strikeouts through early May 2026.

Gregory Omar Santos Career Statistics

Santos has compiled professional statistics across multiple minor league levels and five major league seasons with three different organizations. His minor league career spans the Dominican Summer League, Northwest League, South Atlantic League, Arizona Fall League, and Pacific Coast League. At the major league level, he has appeared in 79 games, primarily in relief roles with the Giants, White Sox, and Mariners.

2025 Season Performance

The 2025 season proved to be a difficult year for Santos with the Seattle Mariners. After joining the organization in February 2024, he struggled to find consistency on the mound. His season was further derailed by injuries that limited his availability throughout the campaign. The right knee inflammation that ultimately required surgery represented a significant physical obstacle that affected his ability to pitch effectively.

Santos appeared in only eight games for the Mariners during the 2025 season, recording a 1-1 record and 5.14 ERA with no strikeouts over seven innings pitched. The lack of strikeout success indicated a decline in his effectiveness compared to previous seasons. The injury placement on April 25 and subsequent surgery ended his season prematurely. Following the conclusion of the 2025 campaign, Seattle made the decision to non-tender Santos, making him a free agent and ending his tenure with the organization.

Despite the challenging season, Santos found an opportunity to continue his professional career by signing with the San Francisco Giants in December 2025. The return to the organization where he first debuted provided him with a fresh start and another chance to contribute at the major league level. His strong performance in spring training with Triple-A Sacramento earned him a promotion to the active roster in late April 2026, setting the stage for a potential resurgence in his career.