This series will examine the Seattle Mariners top 10 prospects as seen by our Mariners insider, Gill Wilson. This list will rank the prospects based on a combination of overall potential, as well as perceived floor and proximity to the majors. The list may change some as it is published if the Mariners make any significant moves that add or subtract top prospects.
#10 – SS Ismael NievesAge: 18
OSA Ranking: #20It speaks to the depth of the Mariners farm system that OSA’s 20th overall prospect is #10 on our list of M’s farmhands, but it speaks more to how much OSA is overrating Nieves. The Mariners fifth round pick from this year’s draft has the potential to be a multiple time all-star at shortstop, but he looks just as likely to be a fringe starter at second base. Nieves’s best tool is his plus power, and he has the potential to have a good eye as well, but his hit tool and his speed are both a 50 grade at best. While he could develop enough to stick at short, his range and arm profile better at 2B. Nieves hammered the ball in his senior year at Doral Academy Charter in Florida, putting up a 1.544 OPS, and he’ll get his first opportunity at pro ball shortly when the Arizona Rookie League starts up. Nieves is one of the farthest away from the majors of any of the Mariners top prospects, and probably has the biggest variance of possible outcomes, but he has the potential to be a star if everything works out.
#9 – SP Octavio OchoaAge: 21
OSA Ranking: #67With the Mariners deciding to target high floor pitchers in the early rounds of the 2021 Draft, Octavio Ochoa was a very fitting pick in the 3rd round. Ochoa thrived in the JuCo ranks at Saddleback College in Southern California, posting a 2.75 ERA while striking out a batter per inning. Ochoa profiles as a middle to back of the rotation pitcher with a three pitch mix. His success at the major league level is completely dependent on him developing his change up, which could be a devastating strike out pitch if he can get it to form. In his first taste of professional baseball, Ochoa has struggled mightily at A Modesto, with a 6.00 ERA and only 4.9 Ks per 9 innings. Another concern with Ochoa is his ability to limit home runs at the major league level. This is not something he has struggled with previously, but scouts see it becoming an issue as he advances. The hope is for Ochoa to be able to step into the rotation at some point in the 2023 season, but he will need to step up his game and develop his change up for that to happen.
#8 – SS Royce LewisAge: 22
OSA Ranking: #58Acquired from Minnesota in exchange for J.P. Crawford, Lewis won’t make his first appearance with a Mariners affiliate until next season due to a torn UCL that required Tommy John surgery. Lewis may not be the flashiest prospect in the Mariners’ system, but he’s a near lock to be a solid major leaguer. Lewis doesn’t have the biggest tools, but he has been praised for his makeup and leadership. He’s a versatile defender who should be more than capable of handling SS with the ability to play Gold Glove level defense at 2B or man all three OF spots if needed. As far as his bat, he is an average contact hitter and could hit 15-20 home runs but will likely never hit in the top half of the lineup. Lewis’s speed may be his best single tool and should allow him to steal around 30 bases. Lewis may not quite be a star, but he should be a very useful piece for the next great Mariners team.
Seattle Mariners Midseason 2021 Top 10 Prospects#7 – SS Joe GotteAge: 22
OSA Ranking: #40Joe Gotte may end up being one of the biggest steals of the 2021 Draft. The Mariners drafted the 22-year-old out of Kent State as a glove-first shortstop, but after his first few weeks of professional ball, some scouts are saying that he could be an above average hitter as well. Gotte is a stellar fielder able to excel anywhere in the infield and possibly play the corner OF positions with some practice. The biggest question with Gotte is just how much his bat will develop, particularly his power. If he can reach the 60 potential power and 50 hit ratings that scouts currently have on him, he could be a perennial 4-5 WAR player with his exceptional fielding ability. Gotte suffered an injury after his first week of pro ball but has since returned. Early returns are a bit mixed, with Gotte posting a 97 OPS+ and striking out in 30% of his plate appearances. If all else fails, Gotte can also pitch a bit and could have a second career as a relief pitcher, albeit not a very good one.
#6 – SP Joe CunningAge: 23
OSA Ranking: #83Continuing with the plan to add high floor pitchers, Mariners GM Will Gibson decided to trade top catching prospect Cal Raleigh to the Twins for SP Joe Cunning. Cunning is a siderarmer who throws in the 97-99 mph range with a full four pitch repertoire. Cunning profiles as a #3-5 starter who should be pitching in the big leagues in the next two seasons. While Cunning will likely never be an ace, he provides a solid SP option who should be ready by the time the Mariners window of competition opens. In his first seven starts for A+ Everett, Cunning has posted a 2.31 ERA although he will need to get his strikeout numbers up if he wants to continue his dominance. There is some concern with Cunning’s control and ability to prevent homers, but these should not prevent him from becoming a bottom of the rotation pitcher at the very least.
#5 – 1B Alex OrtegaAge: 18
OSA Ranking: #19Alex Ortega may be the best overall hitting prospect in a Mariners system filled to the brim with hitters. Ortega was recently signed for the maximum of $5 million as an international amateur free agent. He’s a bit older than the average international signee and has already begun playing in the DSL. Ortega has massive power potential combined with an excellent ability to make contact with the ball. Unlike most power hitters, Ortega does not profile to strike out a ton. If all goes well, Ortega could be a .290 hitter with 40+ home runs. The only downside with Ortega is that he will only ever be able to play 1B, but he shouldn’t be a liability at that position. Ortega’s potential is sky high, but like any IFA signing, he comes with a significant amount of risk.
#4 – LF Robert Hassell IIIAge: 19
OSA Ranking: #126Robert Hassell was acquired along with IF Jordan Groshans from the Colorado Rockies early in the season in exchange for SP Logan Gilbert. Hassell is a 19-year-old corner outfielder who profiles as an excellent hitter with limited defensive abilities. Hassell’s ceiling is likely a .270-.280 hitter with 30-35 homers. For such a young player he has a relatively high floor as well and should become a 4th OF or bench bat at the very least. There is a possibility that he will have to transition to 1B or DH due to a combination of his defensive shortcomings and the Mariners loaded OF. This isn’t to say that Hassell is incapable of playing the outfield, just that the Mariners may have better defensive options. Hassell has been on fire at A+ Everett this season, posting a 167 OPS+ and on pace for 5.6 WAR. Hassell doesn’t have a definite spot on the Mariners team of the future, but he could be the type of player to push this team over the top, whether it be by forcing his way into the lineup or as a trade chip to improve a position of need.
#3 – SP Jeff Russell
We’ve talked about the Mariners desire to add high-floor pitching this year, and that all began with Jeff Russell, the M’s first round draft pick. GM Will Gibson said that Russell was “exactly who we wanted.” Russell was promoted directly to AA, a move that was deemed too ambitious by some, but he has done better than expected, putting up a 2.41 ERA in 9 starts. Russell is expected to be in the majors at some point next season, or early 2023 at the latest. The Mariners hope that Russell can be a top of the rotation starter, and he should be able to fill a key spot as soon as the team is ready to compete. Russell throws a well-developed three pitch mix including a sinker that comes in at 96-98 mph. The biggest concern with Russell is his control; if it develops he could be an ace, if it doesn’t he will likely be a #4 or 5 starter. The control issues have been on full display early on, with Russell walking 5.2 batters per nine innings thus far. His strikeouts and ability to prevent home runs has allowed him to be effective, but he will need to improve his walk rate to be a reliable major league starter. There is also some concern with his ability to go deep into games, but the Mariners don’t seem to be too worried about this. The Mariners seem dead set on fast-tracking Russell to the majors, and we can only hope that he can live up to his promise and anchor the rotation.
#2 – LF Julio RodriguezAge: 20
OSA Ranking: #49If it weren’t for his injury problems this season, we would likely be looking at a 2022 debut for Rodriguez, and it’s still possible that he does debut next year, but the Mariners will likely want to see him get some more plate appearances and defensive work in at AA or AAA next season. Rodriguez is an imposing presence in the box, standing 6’4” and weighing 225 pounds, and he makes his presence known with his light-tower power. Rodriguez isn’t all about power though, as he has an excellent hit tool and an above average eye as well. He does tend to strike out a bit though, and he’s not the greatest defensive outfielder. Rodriguez’s ceiling is similar to Alex Ortega’s, .280-.290 average with 40+ homers, but Rodriguez has the added benefit of being able to play passable OF defense. Rodriguez has only played 33 games this season, but his offensive prowess has been on display in those games, as he has put up a 149 OPS+, although he hasn’t hit as many long balls as would be expected. Rodriguez is destined to be a star, and he should be in the middle of the Mariners lineup for a long time.
#1 – RF Jarred KelenicAge: 21
OSA Ranking: #27Jarred Kelenic’s major league career has gotten off to a rocky start, but the Mariners are still certain that he is the centerpiece of their rebuilding plan. Kelenic is the most complete player in the Mariners system and doesn’t have a true weakness. At his peak, Kelenic should be capable of a .280 average, 30+ homers, 20+ stolen bases, and solid defense at any outfield position. The Mariners will likely use Kelenic primarily as a right fielder, but he can play anywhere in the outfield without being a liability. Kelenic has dominated AAA this season with a .321 average and a 184 wRC+, but he has not been able to replicate that success in 21 games at the major league level. Teammates rave about Kelenic’s work ethic and say that he displays excellent leadership in the clubhouse, especially since he just recently turned 22 years old. Mariners fans have long been looking to Kelenic to start the future of a seemingly cursed franchise, and it’s only a matter of time before he unleashes his potential on the rest of the league.