William Kempner #71
Miami Marlins
- P
- B/T: R/R
- 6' 0"/222
- Age: 24
- William McCullough Kempner
- Status: Active
- Born: 6/18/2001 in San Jose, CA
- Draft: 2022, San Francisco Giants, Round: 3, Overall Pick: 106
- College: Gonzaga
- MLB Debut: 5/05/2026
2026 Stats
| G | W-L | ERA | IP | SO | WHIP |
|---|---|---|---|---|---|
| 19 | 0-3 | 4.56 | 25.2 | 46 | 1.21 |
2026 Stats
| G | W-L | ERA | IP | SO | WHIP |
|---|---|---|---|---|---|
| 5 | 1-0 | 0.00 | 6.2 | 8 | 0.75 |
MiLB Career Stats
| G | W-L | ERA | IP | SO | WHIP |
|---|---|---|---|---|---|
| 110 | 12-11 | 3.33 | 165.0 | 230 | 1.25 |
MLB Career Stats
| G | W-L | ERA | IP | SO | WHIP |
|---|---|---|---|---|---|
| 5 | 1-0 | 0.00 | 6.2 | 8 | 0.75 |
| Year | W | L | ERA | G | GS | SV | IP | SO | WHIP |
|---|---|---|---|---|---|---|---|---|---|
| 2026 MiLB Stats | 0 | 3 | 4.56 | 19 | 0 | 5 | 25.2 | 46 | 1.21 |
| 2026 MLB Stats | 1 | 0 | 0.00 | 5 | 0 | 0 | 6.2 | 8 | 0.75 |
| MiLB Career Stats | 12 | 11 | 3.33 | 110 | 7 | 13 | 165.0 | 230 | 1.25 |
| MLB Career Stats | 1 | 0 | 0.00 | 5 | 0 | 0 | 6.2 | 8 | 0.75 |
- Next MIA Game: 6-13 @ PIT
Splits
| Duration | W | L | ERA | G | GS | SV | IP | H | ER | BB | SO | WHIP |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Last 7 Games | 1 | 0 | 0.00 | 5 | 0 | 0 | 6.2 | 3 | 0 | 2 | 8 | 0.75 |
| Last 15 Games | - | - | --- | - | - | - | --- | - | - | - | - | --- |
| Last 30 Games | - | - | --- | - | - | - | --- | - | - | - | - | --- |
| Last 3 Games | W | L | SV | IP | H | ER | BB | SO |
|---|---|---|---|---|---|---|---|---|
| 6/10 vs AZ | 1 | 0 | 0 | 2.0 | 0 | 0 | 2 | 3 |
| 6/5 vs TB | 0 | 0 | 0 | 1.1 | 1 | 0 | 0 | 1 |
| 5/31 @ NYM | 0 | 0 | 0 | 1.1 | 2 | 0 | 0 | 3 |
2026 :
RP
(5)
More William Kempner
Latest Transactions
| Team | Date | Transaction |
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May 30, 2026 | Miami Marlins recalled RHP William Kempner from Jacksonville Jumbo Shrimp. |
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May 21, 2026 | RHP William Kempner roster status changed by Jacksonville Jumbo Shrimp. |
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May 6, 2026 | Miami Marlins optioned RHP William Kempner to Jacksonville Jumbo Shrimp. |
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May 5, 2026 | Miami Marlins recalled RHP William Kempner from Jacksonville Jumbo Shrimp. |
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March 8, 2026 | Miami Marlins optioned RHP William Kempner to Jacksonville Jumbo Shrimp. |
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November 18, 2025 | Miami Marlins selected the contract of RHP William Kempner from Jacksonville Jumbo Shrimp. |
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August 12, 2025 | RHP William Kempner assigned to Jacksonville Jumbo Shrimp from Pensacola Blue Wahoos. |
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June 10, 2025 | Pensacola Blue Wahoos activated RHP William Kempner. |
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June 10, 2025 | RHP William Kempner assigned to Pensacola Blue Wahoos from Beloit Sky Carp. |
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April 3, 2025 | RHP William Kempner assigned to Beloit Sky Carp from Pensacola Blue Wahoos. |
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February 28, 2025 | RHP William Kempner assigned to Miami Marlins. |
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January 15, 2025 | RHP William Kempner assigned to Pensacola Blue Wahoos. |
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January 15, 2025 | San Francisco Giants traded RHP William Kempner to Miami Marlins for Future Considerations. International Bonus Pool Money. |
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November 3, 2024 | Richmond Flying Squirrels activated RHP William Kempner. |
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September 25, 2024 | RHP William Kempner assigned to Scottsdale Scorpions. |
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August 9, 2024 | Richmond Flying Squirrels transferred RHP William Kempner from the 7-day injured list to the 60-day injured list. |
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April 5, 2024 | Richmond Flying Squirrels placed RHP William Kempner on the 7-day injured list. |
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September 16, 2023 | Richmond Flying Squirrels activated RHP William Kempner. |
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September 16, 2023 | RHP William Kempner assigned to Richmond Flying Squirrels from Eugene Emeralds. |
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June 13, 2023 | Eugene Emeralds activated RHP William Kempner. |
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June 13, 2023 | RHP William Kempner assigned to Eugene Emeralds from San Jose Giants. |
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August 30, 2022 | RHP William Kempner assigned to San Jose Giants from ACL Giants Black. |
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August 11, 2022 | RHP William Kempner assigned to ACL Giants Black. |
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July 28, 2022 | San Francisco Giants signed RHP William Kempner. |
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June 11, 2022 | RHP William Kempner assigned to College Workout. |
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June 11, 2022 | College Workout activated RHP William Kempner. |
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March 17, 2022 | RHP William Kempner assigned to Gonzaga Bulldogs. |
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March 17, 2022 | Gonzaga Bulldogs activated RHP William Kempner. |
+ Show More Transactions