Douglas Alan Mathis
- Bats Right, Throws Right
- Height 6' 3", Weight 220 lb.
- School Central Arizona College, University of Missouri
- High School Show Low High School
- Debut May 12, 2008
- Final Game July 24, 2010
- Born June 7, 1983 in Maryvale, AZ, USA
Pitcher Doug Mathis was drafted in the 34th round of the 2002 amateur draft by the Los Angeles Dodgers out of high school. Going to community college, he was then drafted in the 31st round of the 2003 amateur draft by the Seattle Mariners. Continuing on to the University of Missouri he was drafted by the Texas Rangers in the 13th round of the 2005 amateur draft and finally signed by scout Mike Grouse.
Mathis was the winner in his Major League debut on May 12, 2008. Facing the Seattle Mariners, he pitched a perfect 10th inning in relief, after the Rangers had given up four runs in the bottom of the 9th to tie the score. He was credited with the win when Ramon Vazquez hit a walk-off home run to lead off the 10th for the Rangers, making the final score 13-12.
Mathis became a coach with the Clinton LumberKings in 2017-2018. He moved to the Toronto Blue Jays' chain as pitching coach of the Buffalo Bisons in 2019. In 2020, he returned to the Rangers as bullpen coach for the major league team.