Seattle Mariners boost bullpen with addition of Gregory Santos

The Seattle Mariners went some way towards improving their bullpen, by completing a trade with the Chicago White Sox for Gregory Santos.

Last season, the Seattle Mariners bullpen was one of the best in the Majors. They ranked second in the AL with a 3.48 ERA, while also placing fifth with a 1.26 WHIP and a .232 batting average.

However, there was some concern about how good the bullpen would be in 2024. This was in part due to having to pitch for a whole season without Paul Sewald, as well as losing Justin Topa as part of the recent trade for Jorge Polanco.

Well, the Mariners took a significant step during the weekend, towards significantly improving their bullpen situation. As confirmed on social media, they have acquired reliever Gregory Santos from the Chicago White Sox.

A reasonable return package for Santos

In exchange, the White Sox received pitcher Prelander Berroa (Mariners’ number 15 prospect), outfielder Zach DeLoach (number 25), and a Competitive Balance Round B draft pick. Unlike their return package for Polanco, this didn’t feel like the Mariners giving up too much, to acquire Santos.

Adding the 24-year-old to the bullpen is a massive win for the Mariners; he really is that good. Last year was a breakout campaign for him in Chicago, after only making five combined appearances for the San Franciso Giants in 2021-22.

Santos appeared in 60 games last year, producing a 3.39 ERA, 2.65 FIP and 1.296 WHIP in 66.1 innings. He also recorded a solid 22.8 percent strikeout and a tremendous 5.9 percent walk rate.

However, you can go even further to find out just how effective the righty really was last season. He had the lowest barrel rate in the Majors at 1.5 percent, while his 17 Run Value on his slider was second-most among all pitchers.

In this respect, Santos’ best pitch is indeed his slider, which averaged 92 mph in 2023. However, he also has an effective sinker and fastball, which both averaged 99 mph last year.

The Dominican Republic native also offers the ability to close out games, with him finishing 17 games and accumulating five saves in eight opportunities last year. As much as Andres Munoz and Matt Brash will get the bulk of these types of assignments, it is good for the Mariners that they now have a third reliable option.

Team control for the Seattle Mariners

From a contract perspective the Mariners are in a great position, with Santos not set to become an unrestricted free agent until after the 2028 season. Last year he earned $720,000.

Perhaps the only real concern relates to the former Boston Red Sox international signing missing the end of last season with elbow inflammation. However, while he might not be ready for the beginning of spring training, he’s still projected to make up to eight appearances prior to the regular season.

As you can imagine, the Mariners are delighted with the addition of Santos. President of baseball operations Jerry Dipoto said:

“Gregory is coming off of a season in which he established himself as one of the most exciting young relievers in MLB. His combination of high velocity, dynamic slider and groundball inducing style are all standout traits. He brings the potential for impact to a bullpen group that has been a driving force in our team’s success over the past three seasons.”

What’s your take on the addition of Gregory Santos? Do you believe he now makes the Seattle Mariners’ bullpen the best in the Majors? Let us know in the comments section below.