Mason Peters
Seattle Mariners (A+)P
Age: 22
Bats/Throws: L/L
5'11" / 175
DOB: 12/18/2003
(22 years, 10 months, 15 days)
P
Player Dashboard:
Report: 2026 Updated
Org Rk
Ovr Rk
ETA
FV
19
N/A
2027
35+
Fastball
45 / 50
Slider
45 / 50
Curveball
50 / 55
Changeup
30 / 40
Command
35 / 45
RosterResource
| How Acquired: | Draft |
| Draft: | 2025, Rd: 4, Pick: 17, Ovr: 122 |
| Draft Team: | Seattle Mariners |
| Signing Bonus: | $550,000 |
| College: | Dallas Baptist (Dallas, USA) |
Rule 5 Eligible
Dec'28
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FG
RG
Show
Report: 2026 Updated
Org Rk
Ovr Rk
ETA
FV
19
N/A
2027
35+
Fastball
45 / 50
Slider
45 / 50
Curveball
50 / 55
Changeup
30 / 40
Command
35 / 45
RosterResource
| How Acquired: | Draft |
| Draft: | 2025, Rd: 4, Pick: 17, Ovr: 122 |
| Draft Team: | Seattle Mariners |
| Signing Bonus: | $550,000 |
| College: | Dallas Baptist (Dallas, USA) |
Rule 5 Eligible
Dec'28
News Settings
Article Source
All
FG
RG
Show
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Preseason ProjectionsMinor LeaguesCollege
| Season | Team | Level | Age | W | L | SV | G | GS | IP | divider | K/9 | BB/9 | HR/9 | BABIP | LOB% | GB% | HR/FB | divider | vFA | divider | ERA | xERA | FIP | xFIP | WAR |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2025 | DBU | NCAA | 21 | 4 | 2 | 4 | 20 | 4 | 42.1 | 12.33 | 3.40 | 0.85 | .327 | 69.3% | 4.25 | 4.09 | |||||||||
| 2026 | SEA | A | 22 | 1 | 0 | 0 | 14 | 14 | 50.1 | 12.16 | 2.15 | 0.54 | .262 | 91.1% | 57.7% | 11.1% | 1.43 | 3.44 | 3.54 | ||||||
| 2026 | SEA | A+ | 22 | 0 | 0 | 0 | 4 | 4 | 14.0 | 12.21 | 4.50 | 1.93 | .258 | 79.7% | 54.5% | 30.0% | 4.50 | 5.30 | 3.84 | ||||||
| 2026 | SEA | MiLB | 22 | 1 | 0 | 0 | 18 | 18 | 64.1 | 12.17 | 2.66 | 0.84 | .261 | 88.3% | 56.9% | 16.2% | 2.10 | 3.84 | 3.61 | ||||||
| 2027 | Steamer | PROJ | 23 | 0 | 0 | 0 | 0 | 0 | 1.0 | 6.87 | 4.23 | 1.18 | .291 | 72.4% | 44.5% | 4.50 | 4.82 | 4.79 | 0.0 |
| Season | Team | Level | Age | W | L | SV | G | GS | IP | divider | K/9 | BB/9 | HR/9 | BABIP | LOB% | GB% | HR/FB | divider | vFA | divider | ERA | xERA | FIP | xFIP | WAR |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2025 | DBU | NCAA | 21 | 4 | 2 | 4 | 20 | 4 | 42.1 | 12.33 | 3.40 | 0.85 | .327 | 69.3% | 4.25 | 4.09 | |||||||||
| 2026 | SEA | A | 22 | 1 | 0 | 0 | 14 | 14 | 50.1 | 12.16 | 2.15 | 0.54 | .262 | 91.1% | 57.7% | 11.1% | 1.43 | 3.44 | 3.54 | ||||||
| 2026 | SEA | A+ | 22 | 0 | 0 | 0 | 4 | 4 | 14.0 | 12.21 | 4.50 | 1.93 | .258 | 79.7% | 54.5% | 30.0% | 4.50 | 5.30 | 3.84 | ||||||
| 2026 | SEA | MiLB | 22 | 1 | 0 | 0 | 18 | 18 | 64.1 | 12.17 | 2.66 | 0.84 | .261 | 88.3% | 56.9% | 16.2% | 2.10 | 3.84 | 3.61 | ||||||
| 2027 | Steamer | PROJ | 23 | 0 | 0 | 0 | 0 | 0 | 1.0 | 6.87 | 4.23 | 1.18 | .291 | 72.4% | 44.5% | 4.50 | 4.82 | 4.79 | 0.0 |
Preseason ProjectionsMinor LeaguesCollege
Preseason ProjectionsMinor LeaguesAveragesCollege
| Season | Team | Level | K/9 | BB/9 | K/BB | HR/9 | divider | K% | BB% | K-BB% | divider | AVG | WHIP | BABIP | LOB% | divider | ERA- | FIP- | divider | FIP |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2025 | DBU | NCAA | 12.33 | 3.40 | 3.63 | 0.85 | 31.4% | 8.6% | 22.7% | .227 | 1.25 | .327 | 69.3% | 73 | 71 | 4.09 | ||||
| 2026 | SEA | A | 12.16 | 2.15 | 5.67 | 0.54 | 35.1% | 6.2% | 28.9% | .174 | 0.85 | .262 | 91.1% | 26 | 64 | 3.44 | ||||
| 2026 | SEA | A+ | 12.21 | 4.50 | 2.71 | 1.93 | 31.7% | 11.7% | 20.0% | .208 | 1.29 | .258 | 79.7% | 86 | 102 | 5.30 | ||||
| 2026 | SEA | MiLB | 12.17 | 2.66 | 4.58 | 0.84 | 34.3% | 7.5% | 26.8% | .182 | 0.95 | .261 | 88.3% | 39 | 72 | 3.84 | ||||
| 2027 | Steamer | PROJ | 6.87 | 4.23 | 1.62 | 1.18 | 17.2% | 10.6% | 6.6% | .258 | 1.48 | .291 | 72.4% | 4.82 |
| Season | Team | Level | K/9 | BB/9 | K/BB | HR/9 | divider | K% | BB% | K-BB% | divider | AVG | WHIP | BABIP | LOB% | divider | ERA- | FIP- | divider | FIP |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2025 | DBU | NCAA | 12.33 | 3.40 | 3.63 | 0.85 | 31.4% | 8.6% | 22.7% | .227 | 1.25 | .327 | 69.3% | 73 | 71 | 4.09 | ||||
| 2026 | SEA | A | 12.16 | 2.15 | 5.67 | 0.54 | 35.1% | 6.2% | 28.9% | .174 | 0.85 | .262 | 91.1% | 26 | 64 | 3.44 | ||||
| 2026 | SEA | A+ | 12.21 | 4.50 | 2.71 | 1.93 | 31.7% | 11.7% | 20.0% | .208 | 1.29 | .258 | 79.7% | 86 | 102 | 5.30 | ||||
| 2026 | SEA | MiLB | 12.17 | 2.66 | 4.58 | 0.84 | 34.3% | 7.5% | 26.8% | .182 | 0.95 | .261 | 88.3% | 39 | 72 | 3.84 | ||||
| 2027 | Steamer | PROJ | 6.87 | 4.23 | 1.62 | 1.18 | 17.2% | 10.6% | 6.6% | .258 | 1.48 | .291 | 72.4% | 4.82 |
Preseason ProjectionsMinor LeaguesCollege
| Season | Team | Level | GB/FB | LD% | GB% | FB% | IFFB% | HR/FB | IFH% | BUH% | divider | Pull% | Cent% | Oppo% | divider | Soft% | Med% | Hard% | divider | SIERA | xFIP- | xFIP |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2026 | SEA | A | 2.22 | 16.3% | 57.7% | 26.0% | 11.1% | 11.1% | 41.8% | 24.5% | 33.6% | 64 | 3.54 | |||||||||
| 2026 | SEA | A+ | 1.80 | 15.2% | 54.5% | 30.3% | 20.0% | 30.0% | 50.0% | 26.5% | 23.5% | 77 | 3.84 | |||||||||
| 2026 | SEA | MiLB | 2.11 | 16.1% | 56.9% | 27.0% | 13.5% | 16.2% | 43.8% | 25.0% | 31.3% | 67 | 3.61 | |||||||||
| 2027 | Steamer | PROJ | 20.4% | 44.5% | 35.1% | 4.79 |
| Season | Team | Level | GB/FB | LD% | GB% | FB% | IFFB% | HR/FB | IFH% | BUH% | divider | Pull% | Cent% | Oppo% | divider | Soft% | Med% | Hard% | divider | SIERA | xFIP- | xFIP |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2026 | SEA | A | 2.22 | 16.3% | 57.7% | 26.0% | 11.1% | 11.1% | 41.8% | 24.5% | 33.6% | 64 | 3.54 | |||||||||
| 2026 | SEA | A+ | 1.80 | 15.2% | 54.5% | 30.3% | 20.0% | 30.0% | 50.0% | 26.5% | 23.5% | 77 | 3.84 | |||||||||
| 2026 | SEA | MiLB | 2.11 | 16.1% | 56.9% | 27.0% | 13.5% | 16.2% | 43.8% | 25.0% | 31.3% | 67 | 3.61 | |||||||||
| 2027 | Steamer | PROJ | 20.4% | 44.5% | 35.1% | 4.79 |
Preseason ProjectionsMinor LeaguesCollege
MLB F-Strike%, SwStr%, CStr%, CSW% are from the Sports Info Solution data source.
All MiLB and Pace data are from Statcast.
All MiLB and Pace data are from Statcast.
Preseason ProjectionsMinor LeaguesAveragesCollege
Preseason ProjectionsMinor LeaguesCollege
