IRVING -- One day after the Dallas Cowboys season-ending loss at Washington, coach Jason Garrett said he thought highly of defensive coordinator Rob Ryans ability to cope with an injury-riddled unit throughout the 8-8 campaign.But Garrett was also quick to point out that injuries were not considered an excuse for the teams failures in 2012.Ryan, who joined the Cowboys in 2011 with the promise of greatness, ultimately paid with his job on Tuesday as he was fired two years into a three-year deal, per multiple sources.The Cowboys had the 19th ranked defense in the NFL, while failing to rush the passer or force turnovers on a consistent basis.Blame can be partly attributed to losing four starters to season-ending injuries, including linebackers Bruce Carter and Sean Lee, defensive end Kenyon Coleman and safety Barry Church. Pro Bowl nose tackle Jay Ratliff played in only six games due to a foot injury and sports hernia. Nickel cornerback Orlando Scandrick was also put on injured reserve with a fractured wrist.It should also be noted that Pro Bowl linebacker DeMarcus Ware played the final half of the season limited by shoulder, elbow and hamstring injuries.That doesnt even include having to deal with the tragic death of practice squad linebacker Jerry Brown and the loss of nose tackle Josh Brent after he was charged with intoxication manslaughter. Brent had started in place of the injured Ratliff.Ryan ended the season playing with a number of Cowboys who werent even with the team at the beginning of the season.In the end, it didnt matter as much as the bottom line to Garrett and owner Jerry Jones, who promised last week that uncomfortable times were ahead for the staff at the teams Valley Ranch headquarters.It also didnt help Ryan that his flamboyant and boastful personality was never a good fit with the button-downed Garrett. After making a few statements that turned into bulletin-board material for opposing teams in 2011, Ryan was instructed by Garrett to tone it down before the 2012 season.He did his best stay out of trouble in 2012. But he was flagged for going on the field to jaw with an opposing player in a game against Cincinnati and that didnt sit well with Garrett.Ryan is the second coach to be fired by the Cowboys in as many days, joining running backs coach Skip Peete, who was released Monday.