LL’s top Mariners prospects 2020: 22-19

It’s prospect ranking season! If you’ve missed any of the previous installations, you can catch up on previous lists and the introduction to the series in the main hub here. Today we close out the Top 20 with some MLB-adjacent relievers, as opposed to the other MLB-adjacent relievers we’ll be talking about tomorrow, and an exciting new addition to the infield corps.

22. RHP Dayeison Arias

Arias is a little older than the typical Latin American relief prospect who just finished his first year of full season ball due to signing at a slightly advanced age, but he’s moved quickly through the system so far and been successful at every stop in the low minors. There’s still a chance he runs into the old Double-A buzzsaw, or even stumbles at Modesto this season, but in his seven-inning sample there last year he posted almost exactly the same K-BB numbers as he did in West Virginia, which were in turn almost identical to the numbers he posted at Everett, which were the same as his performance in the DSL. In other words, there’s a lot of consistency here, which isn’t necessarily typical of this kind of profile. Arias has a whippy arm action that creates plus movement on his pitches and a fastball-slider pitch mix that is more than a little reminiscent of Edwin Diaz, and while he doesn’t have Diaz’s elite velocity, he shares an ability to dictate the tone and pace of at-bats. The Mariners recalled him after Arias was drafted to play in LIDOM this off-season, indicating they value keeping the mileage on his arm low, and sent him to high performance camp instead. The 23-year-old Arias could move quickly again this year. -KP

21. RHP Joey Gerber

I present to you, all of my eggs. You may have these, Joey Gerbz. Place them all in your basket. They are yours.

It’s been a long-while since I’ve evaluated a Mariners relief prospect that has generated the level of confidence I have in Gerber succeeding. Essentially a two-pitch pitcher, both offerings are plus or better at times, and when he’s right, he’s damn-near un-hittable. Scouts, teammates, and opposing hitters I’ve spoken with over the last year have all emphasized how tough it is to track his pitches, let alone hit them. The heater has extreme arm-side run and lift. He’s got the Max Scherzer Shot Put thing going for him, allowing the fastball to play up even further. The slider has sharp, late break with good deception. Gerber does have a changeup, but in most cases, he never uses or needs it for that matter. With 74 minor league innings under his belt, “Joey Baby” has punched out 112 hitters and allowed just two home runs along the way. He’s allowed just 30 walks in his professional career. Perhaps his greatest asset, Gerber’s delivery is one of extreme chaos and funk. There’s limbs moving and shaking everywhere, akin to the good ol’ Seattle windstorms he’ll soon grow familiar with. Gerber will receive a good, long look this season, and for my money, is as good a bet as anyone to succeed at the big league level. It’s awfully difficult to grade a reliever a FV of anything more than 45, given their lack of opportunities and volatility, but Gerber certainly has a closer ceiling. That being said, he likely ultimately slots in more comfortably as a late-inning, high-leverage guy for Scott Servais to play with in close contests. -JD

20. 3B Austin Shenton

In another draft, Austin Shenton might not have received the same level of attention as he did this year. But the Mariners went with pitchers nine of their 11 picks in the first 10 rounds. One was senior sign INF Mike Salvatore, in round nine, and the other was Shenton in round five. Seattle hasn’t shown themselves to have a cookie-cutter approach to placing draftees, and it was good to see Shenton graduate quickly to Low-A West Virginia from Short Season-A Everett. Shenton, like Keegan McGovern a year before, posted strong college numbers, making him more suited for the challenge, and his numbers stayed strong. Shenton’s bat-to-ball skills are solid, and the ball comes off his bat hard, but his challenge will be finding a spot on the field to ply his trade. The reviews on his glovework at third base have not been glowing, and I was not blown away seeing him myself. Seattle gave him a bit of work at both second base and left field, where less would be asked of his arm, though his range and speed would be middling. Shenton shares a lot of the traits of Joe Rizzo, in truth, with a defensive toolkit that seems more utility than position-claiming, carried by offensive skills that need to set the tone. Shenton could start at either West Virginia or Modesto next year, but without much competition for 3B reps in the low-minors, he should keep getting a chance to refine his footwork and stick at the hot corner. -JT

19. LHP Aaron Fletcher

This is likely higher than you will see Fletcher other places, and is admittedly based on a small but compelling sample size of watching him firsthand mow through batters in the Arizona Fall League with a slider that seems to have taken a step forward since Fletch was a prospect in Washington’s system. Other relievers might have nastier pure stuff but Fletcher combines a deceptive delivery where he hides the ball well out of a left-handed slot with mid-90s heat and a slider that dives away from lefties and winds up at the back foot of righties. He reportedly also had an average changeup while with the Nationals but we haven’t seen much, if any, of it since he joined Seattle’s system, so that’s something to monitor over a season where he should be knocking at the door of Seattle’s high-variance bullpen by mid-season. -KP