Top 10 Seattle Mariners Prospects for 2021 Fantasy Baseball

If you’re looking for a club to follow while your home team punts its players away, Seattle should be your first stop. Thanks to a shrewd series of signings, draft selections and trades, the rebuild that started in GM Jerry DiPoto’s rhythmic drips and drops is now a tempest gathering fury just off the West Coast. 

Format: Position Player | Age on 4/1/2021 | Highest level played | ETA

1. OF Julio Rodriguez | 20 | A+ | 2021

Perhaps the best young hitter in the minors, Rodriguez has a strong case for the number one overall spot. Concerns exist about his ability to handle elite chase pitches on the outer half, and while that’s true of just about every young hitter, J-Rod’s first move in the box is a slight drift toward third base, and his front leg moves that direction as well. He’s adept at slashing or driving the ball to the opposite field, so I suspect this could be just an aesthetic thing because sometimes the greats just look different and force us to retrain our eyes a little. Might wind up a double plus in hit and power with just enough athleticism to chip in on the base paths.

2. OF Jarred Kelenic | 21 | AA | 2021 

Recently tabbed the top fantasy prospect in baseball by Prospects Live, Kelenic does everything well on a baseball field. Looks like an old Robert Redford out there. Can shoot a frisbee out of the air with one swing of his bat. If we’d had a regular 2020, he almost certainly would’ve pushed his way to the majors. Instead, he spent the season generating as much training site buzz as anyone in the game. Legend has it he once hit home runs on six straight swings. Or maybe that was six straight days. Truth gets foggy at these training sites. Point is he’s ready and should be up for good after now-standard clock-suppressing period.

3. SS Noelvi Marte | 19 | R | 2023

Prospect lists this season are somewhat reflective of each organization’s ability to publicize their own talent. Seattle has a knack for this, even turning some of that responsibility (and a YouTube show) over to Julio Rodriguez. That said, Marte’s ascent is mostly a result of his own extreme physical gifts as a plus athlete across the board who showed he could hang with near-majors pitching at the training site. This winter might be the last chance to acquire him at anything less than top-20-prospect pricing.

4. RHP Logan Gilbert | 23 | AA | 2021

Another ready-now prospect who figures to earn an early promotion, Gilbert is a prototypical workhorse starter at 6’6” 225 lbs with plus conman of a diverse arsenal. He’s dominated so far, limiting walks and home runs while striking out more than a better per inning at every level. I think he can keep that up in the heavy north-pacific air.

5. RHP George Kirby | 23 | A- | 2021

Kirby moonlights as part of a cartoon fight club death cult but aside from that seems about as safe as young pitchers come. Double-plus command is the carrying tool, activating Kirby’s attacks in all parts of the strike zone and even extending the plate like an aged Atlanta arm from the 1990s as he gains the benefit of the doubt never waking anyone. Can he maintain his training site heat deep into games? Time will tell, but if we see Kirby shoving high nineties in the middle innings early this year, he’ll jump up prospect lists and float his way to Seattle by midsummer.

6. RHP Emerson Hancock | 21 | NCAA | 2022

Prospect Hobbs wrote a great blurb while ranking Hancock 4th in his Top 10 College Prospects to Target in Dynasty Leagues, so I’m compelled to paste that here.

“MLB Pipeline has Hancock tabbed as the No. 1 overall pick in this year’s draft, but I’d be surprised to see a name other than Martin or Torkelson called in that spot. Still, Hancock commands four quality pitches, with his 65-grade fastball peaking at 99 MPH and typically sitting 94-97 MPH during starts. His slider and changeup both received grades of 60, while his hard curveball is a 55.

The consensus seems to be that Hancock often relies too much on his duo of breaking pitches and needs to trust his changeup more, which in itself is a plus pitch. If he does so as he develops as a pitcher, his stuff and natural build give him the ceiling of the top-of-the-rotation power pitcher.

Since he got roughed up in two of his four 2020 starts by Richmond and Georgia Tech, he’s unlikely to go number one overall in the 2020 Draft. His college track record (16-7, 3.47 ERA, 1.07 WHIP, 206 K) still provides enough evidence to illustrate the upside Hancock possesses when taking into account his steady arsenal of pitches. What’s more, he improved both his K/9 and BB/9 from his career totals in his shortened 2020 campaign (12.8 K/9, 1.1 BB/9). When it comes to an arm like this, it’s often most important to see evidence of the guy harnessing his stuff and going after hitters because they simply outmatch the competition the majority of days they’re on the mound.

Although Hancock won’t be the best bang for your buck (depending on how your waiver wire functions) and there may be someone in your league who values him too highly, he’s too good to be any lower on your radar than this spot indicates.”

Thanks, Hobbs!

7. OF Zach DeLoach | 22 | NCAA | 2023

Could make a case for several players here but none that can truly contend with DeLoach for topside. After slashing .200/.316/.294 in 56 games as a Sophomore in the SEC, DeLoach went nuts on the cape (.353/.428/.551 in 37 games) then jumped another level in his junior year at Texas A&M (.421/.547/.789 in 18 games). What a difference a year can make. Seattle has a good idea what they’re doing on the scouting and development side. Even before his sophomore struggles, DeLoach hit well with wooden bats in the Northwest League (.323/.409/.495 in 51 games), so I’m inclined to just give him a mulligan on his sophomore season and treat him like an elite college bat who struck out just thrice and walked 14 times over his final 18 games at the level.

8. OF Taylor Trammell | 23 | AA | 2022

A power speed outfielder who doesn’t hit or throw particularly well, Trammell’s reputation in prospect circles has long exceeded his likely fantasy value. Non-zero chance he never gets much of a big league opportunity in this loaded outfield. He remains on the list more because Seattle is good at helping hitters than because I have any real confidence in the player.

Red flags to note for future and Jazz: if prospect writers start telling you stories about how cool a guy seems—how friendly he is in interviews or how happy he is with his teammates—be wary of buying that prospect. His value will likely be inflated human intangibles, a genie that will never go back in the bottle. Which, now that I mention it, makes me wonder if I should flip Julio and Jarred again for the fifteenth time. Might be right to push that prospect up lists sometimes because confidence is key to baseball, of course, but Trammell and Jazz are part of some developing tastemaker theories. Cool guys and fall league standouts are dangerous. 

9. LHP Brandon Williamson | 22 | A- | 2022

While he’s thrown just 15.1 pro innings at low A, Williamson is one of my pitching picks to click in 2021. He’s a high-strikeout ground ball inducer, and it’s tough to go wrong with that profile, especially as a 6’6” 210 lb lefty. If he can maintain at least average command, his potential mix of four average or better pitches (fastball, curve, slider, change) could set him up for a long big league life. More importantly for our purposes, I think he’ll dominate the minors this year and enter next season safely inside some top 100s. If I have to choose any M’s arm at current cost, it’s Williamson.

10. OF Jonatan Clase | 18 | R | 2024

Clase caught some eyeballs in 2019 after posting 31 steals in 63 games to go along with a 147 wRC+ and nearly 1/1 K/BB ratio in the DSL, but at 5’8” 155 lbs, he’s going to have to keep proving it to earn any real long-term look. Luckily, he has a great idea of what he can do at the plate and plays to his strengths, maximizing his tiny strike zone with a discerning eye. This will be the determining factor in his future. If he can recognize spin and win his walks, he’ll be the type of pesky, deep-counts lead off bat any team (or fantasy team) would be happy to have.

Thanks for reading!

I’m @theprospectitch on Twitter.