Breske was the team's defensive coordinator for each of head coach Mike Leach's three seasons at the school. Before joining Washington State, Breske was Montana's defensive coordinator.
The Cougars trailed 31-0 before mounting a small comeback against Washington. Washington State finished the season with a 3-9 record. Defensively, the group allowed 443 yards per game during the season, placing it No. 98 in the country among FBS teams and No. 11 in the Pac-12 conference.
Washington State also finished at No. 115 in scoring defense, and the Cougars forced only eight turnovers over 12 games in 2014.
Linebackers coach Paul Volero has also been fired, according to Feldman.
Leach has not confirmed these moves.