Jeffrey Wayne Karstens
- Bats Right, Throws Right
- Height 6' 3", Weight 175 lb.
- School Grossmont College, Texas Tech University
- High School Mount Miguel High School
- Debut August 22, 2006
- Final Game October 1, 2012
- Born September 24, 1982 in San Diego, CA USA
Karstens was the ace for Team USA in the 2007 Baseball World Cup, going 2-0 with a 0.69 ERA. He was the only pitcher with multiple wins on the club, which became the first US team in over 30 years to win Gold in the Baseball World Cup. Karstens shut down the Mexican national team and South Korean national team, both of whom finished in the top 8 in the tournament.