Mariners promote Joey Gerber to big league club among other moves

On Tuesday, the Mariners selected the contract of RHP Joey Gerber adding him to the 40-man roster and the active 30-man roster. He will be in uniform for the Mariners tonight.

Also being added to the big league club, Seattle recalled LHP Taylor Guilbeau from the alternate training site.

In corresponding moves, the team placed RHP Kendall Graveman on the 10-Day IL as neck spasms have been bothering him. The Mariners also optioned RHP Zac Grotz to the alternate training site.

Gerber (6-4, 215) has performed at every level for the Mariners since being selected in 2018. In 74.1 minor league innings, Gerber owns a 2.42 ERA and a 1.157 WHIP. He’s punched out 112 batters whilst issuing 30 free passes. He was especially dominant last summer in Arkansas where he pitched 22.2 innings for the AA Travelers to the tune of a 1.57 ERA and 30 Ks to just 7 walks.

An 8th round selection, Gerber was a standout at the University of Illinois, operating out of the bullpen exclusively. In 67 collegiate innings, the tall redhead struck out 91 batters, walking 31.

Since going pro he’s only gotten better.

In college, Gerber was mostly 93-95 with an above average slider and a changeup that would flash at times. He’s added notable velo since then, now routinely 95-98 with a slider that is more often than not a plus offering. The changeup has gone by the wayside, and is rarely deployed at this point.

The fastball is certainly Gerber’s best offering, and he can manipulate it how he sees fit. It’s a 2500-2600 RPM heater with ride and run up in the zone, occasionally showing sink at the bottom of the zone. The horizontal and vertical movement he gets on his fastball is pretty hellish for right-handed batters, especially as it comes from a place of pretty extreme deception. More on that shortly.

The slider is his second primary, spinning to the plate at 2400-2500 RPMs. It’s a tight slider that he commands well with gyro and transverse spin leading to impressive sweep and depth. It tunnels the fastball really, really well, especially as everything Gerber has dances out of the hand. It’s a pretty good strikeout offering.

Gerber’s best attribute might be his delivery. It’s a quick crossfire move with lots of funk. The ball looks like it explodes right out of his shoulder. The arm action is very, very short — akin to Max Scherzer of the Nationals. It’s a really tough operation for batters to track, and an uneasy plate appearance as pretty much nothing comes out of his hand straight.

Gerber has had his issues with walks in the past, but not to the alarming degree that Mariners fans have seen from the current bullpen. You’ll see his command waver from time to time, but I wouldn’t go as far as to call it a liability. In fact, Gerber’s command really improved over the final couple months at AA last summer.

There’s definitely a high-leverage, late inning profile here and he may have the opportunity to earn that label as the season draws on. For now, Scott Servais and the Mariners organization likely wants to see what they have in Gerber and whether or not he can be a reliable piece to the ever-evolving puzzle just beyond the left-center field fence.

Rated the Mariners 19th best prospect by MLBPipeline and 25th best prospect by Baseball America, there’s certainly some respect on Gerber’s name in prospect circles. It takes a lot for a definitive relief pitcher to rank among an organization’s best prospects. There’s some reputation here. He’ll be a fun addition to what’s been a late inning little shop of horrors for the Mariners.