The Bills have been talking up Merriman all summer, with head coach Chan Gailey notably and repeatedly telling reporters that he thought Merriman was back to his old self. Glazer, however, reports that the Bills believe that Merriman is better suited to a 3-4 defense - and with the team moving to a 4-3, the fit wasn't right. Merriman had seen decreasing playing time in training camp practices and in the second pre-season game, so this move was telegraphed a bit.
Personally, I'm not sure that I buy the idea that Merriman was released because of poor scheme fit. Good pass rushers can be shoehorned into any scheme. Merriman did not look notably better than he did at the outset of the 2011 season, when he was a dependable run defender, an invisible pass rusher and seemingly a moment away from his next injury at all times. The Bills are clearly trying to give Merriman his best chance to catch on somewhere else; we're left to vaguely wonder what might have happened between Gailey's ardent praise and today.
With Merriman now out of the picture, young veteran Kyle Moore - who has been a pleasant surprise throughout summer practices - is a very strong bet to make the team as the fourth defensive end, where he'll rotate in behind Mario Williams, Mark Anderson and Chris Kelsay.