How much will Gregory Santos’ arrival to bullpen help the Mariners?

Gregory Santos has been a member of the Seattle Mariners since February, but it wasn’t until Tuesday night that he played in actual competition for the organization.

Mariners sign former All-Star reliever, make roster move at catcher

The 24-year-old right-hander had been sidelined since spring training with a lat injury, one that came with multiple setbacks. He’s been on track over the last month, however, and is finally on a rehab assignment with the Triple-A Tacoma Rainiers.

Santos’ first appearance went well Tuesday night in an 8-7 Rainiers win over the Salt Lake Bees at Cheney Stadium. He threw a scoreless sixth inning on 13 pitches, working around a lone hit while logging a strikeout on a 98 mph fastball.

Gregory Santos strikes out the first batter he faces on Major League rehab with a 98 mph fastball pic.twitter.com/461OihBinx

— Tacoma Rainiers (@RainiersLand) July 3, 2024

With a few more outings under his belt in the minors, it shouldn’t be long before Santos is activated and joins Seattle’s bullpen. That leads to the big question: How much will his arrival impact the Mariners, who are currently clinging onto a three-game lead in the AL West?

ROOT Sports Mariners analyst and former MLB third baseman Mike Blowers weighed in during his weekly Tuesday visit with Seattle Sports’ Wyman and Bob.

Blowers said the addition of Santos will give Mariners manager Scott Servais something he’s been without due to Matt Brash, a key high-leverage arm for Seattle the past two years, missing this season due to Tommy John surgery.

“With his fastball, he’s going to be upper 90s – he’ll be right there with (Ryne) Stanek and (Andrés) Muñoz with his heater,” Blowers said of Santos. “The only thing that I don’t really know about is how consistent he’s going to be with his command. But that being said, if you have him and Stanek and Muñoz, Scott can work the bullpen on the back end of things when they have a lead. Even if it’s a one-run lead, they can shorten the game on teams, and I think that’s something they have been missing without Brash.”

Santos opened some eyes in 2023 with the Chicago White Sox with his stuff on the mound, and though he finished the year with a 3.39 ERA, his ERA was down as low as 2.53 ERA in mid-August. He had a strong 2.65 FIP and 3.88 strikeouts per walk ratio for the year, as well.

“He’s a swing-and-miss guy, and that’s something that every team… (wants) at the back end of the game,” Blowers said.

You can hear the full Wyman and Bob conversation with Blowers in the podcast at this link or in the player near the top of this post.

Revisiting the Santos acquisition

The reviews of Santos at the time of the Mariners’ trade for him were positive. Here’s what a couple insiders had to say then:

• Jon Morosi of MLB Network (to Seattle Sports’ Wyman and Bob): “They got someone who I believe can be a closer, and they got someone who has closer upside. I thought he was a breakout performer on a team that we weren’t really watching carefully last year. … He’s been on my radar for a while as someone that can be a breakout performer.”

• Former White Sox and current Tigers broadcaster Jason Benetti (to Seattle Sports’ Brock and Salk): “I do think the ceiling is pretty substantial. And the walk rate can come down. He wasn’t always great after getting ahead of hitters. Sometimes it kind of faded on him, the at-bat did. I just think with some more maturity of major league pitching time, there’s a fantastic arm in there. There really, really is.”

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