Buffalo Bills' Rex Ryan won't commit to retaining Dennis Thurman

Rex Ryan just completed his first season as head coach of the Buffalo Bills. In that 8-8 season, the Bills' defense fell massively short of expectations - but more intriguingly, it was also easily the worst defense that Ryan has fielded in his 11 years as a defensive play-caller in the NFL.

It was interesting, then, that Ryan would not verbally commit to bringing back defensive coordinator Dennis Thurman in an otherwise completely innocuous year-end news conference conducted Monday afternoon at One Bills Drive.

Rex Ryan didn't say for certain that Dennis Thurman would be the defensive coordinator of the Buffalo Bills in 2016.

— Matthew Fairburn (@MatthewFairburn) January 4, 2016

It's a fair question to ask, given the availability of former Ryan defensive coordinator Mike Pettine and his brother, Rob Ryan, and given the struggles of the Bills' defense this season. But Ryan has also touted Thurman as a future head coach on numerous occasions, and the two have worked together for 13 years between Baltimore, New York, and now Buffalo (although Thurman was a defensive coordinator for only three of those). It still seems more likely than not that the Bills, running Ryan's defense (not Thurman's), will stay the course heading into the 2015 season. That's easily arguable even as Ryan left that door open on Monday.

Still, there is no question that improving defensively should be the Bills' point of emphasis this offseason. Not only was 2015 Ryan's lowest finish as an overall defense in 11 years, but it was also the first time his defense didn't finish in the Top 5 in the league in any defensive category. Improvement is imperative across the board.