Seattle Mariners in Preseason Top 500
Glossary for future grades: h-hit tool, p-power tool, s-speed tool, fb-fastball, sl-slider, cv-curveball, ch-change-up, ct-cutter, fv-future value overall.
| NO. | NAME | POS | B/T | FUTURE GRADES | LEVEL | AGE | ETA |
| 1 | Harry Ford | C | R/R | 55h-50p-60s-55fv | Low-A | 20 | 2025 |
| 2 | Bryce Miller | SPRP | R/R | 70fb-45cv-55sl-50ch-55fv | AA | 24 | mid-2023 |
| 3 | Gabriel Gonzalez | OF | R/R | 45h-60p-40s-55fv | Low-A | 19 | 2025 |
| 4 | Jonatan Clase | OF | L/R | 55h-40p-70s-50fv | Low-A | 20 | 2024 |
| 5 | Emerson Hancock | SP | R/R | 60fb-50cv-55sl-55ch-50fv | AA | 24 | mid-2023 |
| 6 | Lazaro Montes | OF | L/R | 50h-60p-50s-50fv | R (DSL) | 18 | 2026 |
| 7 | Felnin Celesten | SS | S/R | 50h-55p-55s-50fv | n/a | 17 | 2027 |
| 8 | Cole Young | SS | L/R | 60h-40p-55s-50fv | Low-A | 19 | 2026 |
| 9 | Michael Arroyo | SS | R/R | 55h-45p-50s-45fv | R (DSL) | 18 | 2026 |
| 10 | Taylor Dollard | SP | R/R | 50fb-45cv-50sl-50ch-45fv | AA | 23 | mid-2023 |
| 11 | Bryan Woo | SP | R/R | 50fb-50sl-50ch-45fv | High-A | 23 | 2025 |
| 12 | Prelander Berroa | SPRP | R/R | 60fb-55sl-50ch-45fv | AA | 23 | mid-2023 |
| 13 | Tyler Locklear | 3B | R/R | 45h-55p-45s-45fv | Low-A | 22 | 2025 |
| 14 | Cade Marlowe | OF | L/R | 45h-45p-55s-45fv | AAA | 26 | mid-2023 |
| 15 | Robert Perez Jr. | 1B | R/R | 45h-55p-40s-45fv | High-A | 23 | 2024 |
| 16 | Axel Sanchez | SS | R/R | 50h-45p-45s-45fv | Low-A | 20 | 2025 |
| 17 | Walter Ford | SP | R/R | 60fb-50sl-45ch-45fv | n/a | 18 | 2026 |
| 18 | Zach DeLoach | OF | L/R | 50fb-50p-55s-45fv | AA | 24 | mid-2023 |