Scheme changes go hand-in-hand with personnel changes. Defensive tackle Dwan Edwards was brought in back in 2010 as part of the Buffalo Bills' plans to implement the 3-4 defense. He had plenty of experience in that front in Baltimore and carried that experience with him to Buffalo.
Edwards has started 24 games the past two seasons, and his $4.1 million base salary for 2012 would have been easily justifiable under those circumstances.
But the whole game changed when the Bills named Dave Wannstedt the defensive coordinator and married themselves to the 4-3 scheme. That, in essence, forced Edwards into a backup role, with defensive tackles Marcell Dareus and Kyle Williams locked into the starting spots.
And that, in turn, has led to the release of Edwards, according to Sal Maiorana of The (Rochester, NY) Democrat & Chronicle.
There isn't a position on the roster where $4.1 million is a justifiable salary for a backup. That's starter money. That made him an easy target as a potential cap casualty.
It could also mean he's not yet done with the Bills.
By all accounts, he had an impressive preseason, and who knows—at the right price, he could be back.
Right now, though, it's time to look forward with the Bills' current situation at defensive tackle. Spencer Johnson remains on the roster, and although his cap number is pretty high at $3.5 million for the 2012 season, he's the best backup they have behind Dareus and Williams.
The release of Edwards opens up a spot for Kellen Heard or Jarron Gilbert to sneak onto the roster. Heard's massive frame—6'6", 348 pounds—makes him a great fit in the rotation as a run-stuffing defensive tackle. He played 14 games with two starts and logged two sacks and a forced fumble in that time.
Gilbert is best known for his amazing display of physical freakishness when he leaped out of a pool and onto the deck prior to being selected in the third round by the Bears in the 2009 draft. He has good end-tackle versatility, which makes him a good fit if the Bills decide to flex back and forth between the 3-4 and 4-3.
Scheme versatility doesn't appear to be in the Bills future, though, and as the Bills move away from the 3-4 defense, they felt comfortable moving away from the 3-4 defensive end. Now, it's time to see if they can move forward in the 4-3 with the pieces in place.
Erik Frenz is the AFC East lead blogger for Bleacher Report. Be sure to follow Erik on Twitter and "like" the AFC East blog on Facebook to keep up with all the updates. Unless specified otherwise, all quotes are obtained firsthand.