I don't see a huge IDP fallout from this switch. I might bump him down just a couple spots out of pessimism because it is something new and there is a touch of uncertainty. But the bottom line is Poz is a stud and he'll continue to be a stud. In my book, he's still a top 10 LB that will be the cornerstone of your IDP lineup.
The departure of Posluszny leaves the Bills with Andra Davis and rookie Kelvin Sheppard as the prospective starters at inside linebacker in the 3-4 defense.
There are numerous options for the Bills to consider in free agency if they opt to replace Posluszny with a veteran from another team. Among them are San Diego free agents Kevin Burnett and Brandon Siler and Packers inside linebacker Nick Barnett, who was informed by Green Bay Tuesday he will be released on Thursday. Burnett played for Bills outside linebackers coach Bob Sanders in Green Bay.
To me this is the biggest IDP news to come out of free agency so far. And yes, at the moment of writing this, I am aware the Quinton Mikell has signed with the Rams. And I'm definitely very intrigued, but you have to wonder why the Eagles have been so disappointed with him as well. Craig Dahl is still there at SS and I believe Mikell will be the Rams starter, but I'm not so sure he'll put up better IDP numbers than Dahl would have. We'll see what news comes out during the short training camp period regarding this position.