Mariners Lose 26-Year-Old Pitcher To Giants In Free Agency

A chance for this disappointing ex-Mariner to work his way back

Sep 2, 2025; Denver, Colorado, USA; General view of San Francisco Giants caps and gloves during the sixth inning against the Colorado Rockies at Coors Field. Mandatory Credit: Ron Chenoy-Imagn Images | Ron Chenoy-Imagn Images

The Seattle Mariners' bullpen was generally quite good this season, but not everyone who threw innings lived up to that identity.

One pitcher who was a disappointment, because he'd had success for the Mariners in the past, was right-hander Gregory Santos. The 26-year-old pitched just seven innings before undergoing knee surgery, the second-straight season he couldn't stay healthy, and allowed four earned runs in those innings.

In late November, when the Mariners had to add some prospects to the 40-man roster to protect them from the Rule 5 Draft, they decided to non-tender Santos, who would have been eligible for arbitration for the first time in his career had he remained on the roster past that deadline.

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Gregory Santos joins Giants on minor-league deal

Santos has already had something of a journeyman career, and this winter, he wasn't able to find a major league contract. He'll have to work his way back onto a 40-man roster with a new, but familiar team.

On Tuesday, Dominican baseball reporter Mike Rodriguez reported that Santos and the San Francisco Giants were in agreement on a minor-league contract for the upcoming season with an invitation to spring training.

Santos came up in the Giants organization, coming to the club in the 2017 trade that sent Eduardo Nuñez to the Boston Red Sox and spending 5 1/2 years there. He was designated for assignment at the end of the 2022 season, after making his major league debut the year before and allowing seven earned runs in five major league appearances for San Francisco.

Santos looked so promising in 2023, pitching to a 3.69 ERA with a 2.25 FIP in 66 1/3 innings, that it was surprising to see him fall off the radar. But teams need relievers to stay healthy, and with elbow and knee issues in back-to-back seasons, Santos wasn't there when the Mariners needed him.

The arm talent remains impressive, but Santos will have a lot to prove in his return to San Francisco.

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