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← Miami Marlins

Pitcher · #71

William Kempner

Bats/Throws
R/R
Height
6' 0"
Weight
222 lb
Born
2001-06-18
Birthplace
San Jose, CA, USA
MLB debut
2026-05-05
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Pitching

Club G IP H R ER BB K BF ERA
MLB Miami Marlins 9 12.1 8 4 4 4 14 50 2.92
AAA Jacksonville Jumbo Shrimp 24 31.2 20 15 14 21 52 137 3.98
Total 33 44.0 28 19 18 25 66 187 3.68

Pitching

Club G IP H R ER BB K BF ERA
AAA Jacksonville Jumbo Shrimp 2 1.1 1 0 0 1 4 6 0.00

Pitching

Club G IP H R ER BB K BF ERA
AAA Jacksonville Jumbo Shrimp 9 12.0 12 11 11 10 28 59 8.25

Pitching

Club G IP H R ER BB K BF ERA
MLB Miami Marlins 3 3.1 2 0 0 0 4 12 0.00
AAA Jacksonville Jumbo Shrimp 8 12.1 2 3 2 5 14 45 1.46
Total 11 15.2 4 3 2 5 18 57 1.15

Pitching

Club G IP H R ER BB K BF ERA
MLB Miami Marlins 3 5.2 1 0 0 2 6 21 0.00
AAA Jacksonville Jumbo Shrimp 5 6.0 5 1 1 5 6 27 1.50
Total 8 11.2 6 1 1 7 12 48 0.77

Pitching

Club G IP H R ER BB K BF ERA
MLB Miami Marlins 3 3.1 5 4 4 2 4 17 10.80

Pitching

Club G IP H R ER BB K BF ERA
MLB Miami Marlins 4 4.0 1 0 0 2 6 16 0.00

9 transactions in 2026

  • Aug 21 Miami Marlins transferred RHP William Kempner from the 15-day injured list to the 60-day injured list. Right elbow sprain.
  • Jul 12 Miami Marlins placed RHP William Kempner on the 15-day injured list. Right elbow sprain.
  • Jul 3 Miami Marlins recalled RHP William Kempner from Jacksonville Jumbo Shrimp.
  • Jun 16 Miami Marlins optioned RHP William Kempner to Jacksonville Jumbo Shrimp.
  • May 30 Miami Marlins recalled RHP William Kempner from Jacksonville Jumbo Shrimp.
  • May 21 RHP William Kempner roster status changed by Jacksonville Jumbo Shrimp.
  • May 6 Miami Marlins optioned RHP William Kempner to Jacksonville Jumbo Shrimp.
  • May 5 Miami Marlins recalled RHP William Kempner from Jacksonville Jumbo Shrimp.
  • Mar 8 Miami Marlins optioned RHP William Kempner to Jacksonville Jumbo Shrimp.