The Dallas Cowboys informed defensive coordinator Rob Ryan on Tuesday he would not be returning to run the team's defense in 2013-14.
Ryan had one year remaining on a three-year contract.
"I want to express my appreciation to Rob for all of his efforts and contributions to the Cowboys over the past two years," Cowboys coach Jason Garrett said in a statement. "At this time, the decision has been made to move forward in a different direction philosophically on defense. I have an immense amount of respect for Rob as a person and as a football coach and I wish him and his family the very best."
Ryan's defense finished 19th overall, 17th against the run and 21st against the pass.
His defense missed five defensive starters due to injuries and two more key backups.
"I inherited a team that was 31st in the league in defense and made them better," Ryan told ESPNDallas.com's Tim MacMahon. "I (expletive) made them a hell of a lot better. I'll be out of work for like five minutes."