Sleeper Prospects to Watch for the Mariners in 2023

Seattle Mariners Summer Workouts
Seattle Mariners Summer Workouts / Abbie Parr/GettyImages

The Mariners started last season with the top-rated farm system in the game. The graduations of George Kirby, Jarred Kelenic, Julio Rodriguez, and Matt Brash, along with trades of Noelvi Marte, Edwin Arroyo, and Brandon Williamson, dropped the farm down a peg or two. However, there are still waves of talent in the system. If you are close to any Mariner affiliates, keep an eye on these sleepers. 

Mariners Dominican Summer League (DSL)

A new darling of prospect writers, shortstop Felnin Celestin, should be on everyone's watch list, but there is another lesser-known youngster to follow. Sebastian De Andrade is a catcher out of Venezuela who should infuse more confidence in the Mariner backstop pipeline. Because right now, the catching talent is lacking besides what is at the major league level (Raleigh, Murphy, Hummel). 

Physically, De Andrade is built like Mariner's top prospect, Harry Ford, but that is where the similarities end. He doesn't possess the elite athleticism of Ford, as he is more of a traditional backstop in the mold of Christian Vazquez. The seventeen-year-old should stay in the DSL all year as the team works further to develop him on the offensive side of the game. 

Honorable Mention: Kendall Meza (RHP)

Mariners Single A: Modesto Nuts

This team is stacked and should be in the year's first half. Most fans know about former first-round picks Harry Ford and Cole Young, but if you have a chance, check out Michael Arroyo. The athletic middle infielder spent last year in the Dominican Summer League (DSL) flashing a proper 'control the zone' approach (13.6% BB – 16.6% BB). This approach should serve him well in Modesto as he adjusts to higher-level pitching. 

The 18-year-old Venezuelan possesses elite bat-to-ball skills; scouts say his defense is above average. Age will keep him in Modesto all year, as he will be one of the youngest players in the Cal league. 

Honorable Mention: Lazaro Montes (OF)

Mariners High-A: Everett Aquasox

When President of Baseball Operations Jerry Dipoto sent top prospects Noevi Marte and Edwin Arroyo to Cincinnati, he handed the shortstop position to a 19-year-old with a slick glove and developing bat. Axel Sanchez played most of the year at Modesto but finished in Everett. The uber-athletic shortstop is already elite defensively, routinely making jaw-dropping plays in the middle of the diamond. Baseball America recently recognized him as the best defensive infielder in the system. 

The actual development was on the offensive side of the game. Sanchez took huge strides last year, accumulating a .305/.401/.605 slash line. His strikeout rates are a little concerning (26.5%), so there is probably a need to adjust to more of a J.P. Crawford-type approach. However, the walk rates are already in a good place (9.9%). Look for Sanchez to spend most of the year in Everett and get a taste of Arkansas if he continues to flash. 

Honorable Mention: Tyler Locklear (1B/3B)

Mariners AA: Arkansas Travelers

Pitching is the name of the game in Arkansas, where Bryce Miller, Emerson Hancock, Prelander Berroa, and Taylor Dollard were firing on all cylinders in 2022. Starting pitcher Bryan Woo should join them here as the team continues to build him up after the 2021 Tommy John surgery. 

Woo shined in the Arizona Fall League, taking player of the week honors. Last year, the team managed his workload, keeping starts under five innings. 2023 should mean fewer training wheels and more chances to flash an upper 90's fastball and high-velocity slider. There still is some discussion about where Woo ends up, either in the bullpen or as a starter. That will depend on his development of the changeup. 

Honorable Mention: Kaden Polcovich (IF/OF)

Mariners AAA: Tacoma Rainiers

At 24 years old, Zach Deloach is getting to the point where he is a little older for the league. If he puts it together, though, he could end up in Seattle as a fourth outfielder. What does that mean? The former Texas A & M Aggie will have to add more power to his approach. He authored a .258/.360/.409 slash line in Arkansas last year while leading the league in walks (77). 

Deloach’s opportunity in Seattle depends on the success of the prospects ahead of him (Kelenic, Trammell, Marlowe). One thing he has above them is his control of the zone approach, as he led the league in walks in 2022 (77). 

Honorable Mention: Cade Marlowe (OF)

There is a ton of talent in the lower levels, which we'll work to cover throughout the year. Meanwhile, if you are near the Mariner affiliates, head down to the stadium for what sounds like an exciting year.