It's tough to run this kind of post when your team doesn't even have a head coach in place. That's the case in Buffalo, where the Bills are set to interview their second head coaching candidate at some point Thursday. Without a concrete idea of the types of offensive and defensive systems the team will be employing in 2010, it's tricky to guess which players will be around, because not every player fits every scheme.

So, naturally, the list we're about to share with you is subject to change. (And yes, it's an opinion piece. Obviously.)

No matter which schemes the Bills end up using, I think the following 21 players are safe in Buffalo. There are a variety of reasons that players make this list, but the most prominent among them are centralized around contract status, overall value and the philosophies laid out by GM Buddy Nix at his introductory press conference. Most of these players are scheme versatile, so in most cases, the team should hang onto these players regardless of who the next head coach is.

The full list of players is after the jump. We welcome the debate that is sure to arise in the comments section.

QB Ryan Fitzpatrick. Intelligent enough to pick up a new offense quickly. Proved that he can throw the ball with enough zip to be successful in inclement weather conditions, something Nix has mentioned as important. Can win your team some games from a backup slot. Fitzpatrick is a guy that a team can rally around if he's thrust into the lineup; he has his teammates' confidence. Should be back in a backup capacity only.

RB Fred Jackson. Pretty much a no-brainer. Can do it all, and will be a valuable asset no matter who the next head coach is.

WR Lee Evans. In the midst of playing out a large contract extension, which ensures that he'll be here. It helps that he's a pretty good player that'll work well in any offensive system, and he's a true team player. Get this guy a quarterback. Please.

TE Shawn Nelson. Nix mentioned briefly his belief that the Bills' 2009 draft class was a strong one, so most of those guys should be back. Nelson possesses tons of untapped potential, and though he had a quiet rookie year, he made some very athletic plays for his offense.

OT Brad Butler. Not much will be known about the direction of the battered offensive line for a while, but Butler should be kept around for two reasons: he's a solid player, and he's in the midst of a very reasonable five-year extension. Will he start? That's up for debate, but solid offensive linemen aren't exactly available 24/7/365.

OG Andy Levitre. Was Buffalo's best lineman in '09 as a rookie second-round pick. Mobile and tough, Levitre has a bright future as an interior lineman.

C/G Eric Wood. Obviously, his inclusion on this list is contingent on his recovery from the gruesome leg injury he suffered in November. He's a big, tough, mobile, smart kid that belongs in the pivot - and if he's healthy in 2010, don't be shocked if he ends up there.

C/G Geoff Hangartner. He's got three years left on his deal, and while he isn't spectacular by any means, he's durable and smart. Maybe he's only a depth player next year - that's how in-flux the line situation is at this point - but he's most certainly earned a place on next year's team.

DE Aaron Schobel. Yes, he might retire - and those chances skyrocket if Schobel is less than enthused with the Bills' coaching hire. If he plays, he's got more than enough left in the tank - as well as the contract status - to stick as a pass rusher, even if the Bills employ a 3-4 scheme.

DE Aaron Maybin. Has his work cut out for him impressing a new regime, regardless of what scheme he's in. But he's a young guy with a modest contract and a ton of potential, so he's not going anywhere any time soon.

DT Marcus Stroud. Might be the most iffy name on the D-Line list aside from Schobel, because at this point, he's pretty strictly a 4-3 DT. Not very scheme versatile. But he got a four-year extension last year, and that contract should keep him in Buffalo for another year regardless of scheme. (Notice, by the way, that Buffalo has yet to interview a coach that exclusively runs a 3-4 defense.)

DT Kyle Williams. Young, improving - to the point that he's a Pro Bowl alternate - and in the middle of a lengthy, modest contract extension. He, too, isn't overly scheme versatile, but he'll be here because he's good enough to be here.

LB Paul Posluszny. Like him or not, he's a good player and picks up defenses quickly. Buffalo is so desperate for depth at linebacker that there is virtually no chance that Posluszny goes anywhere; he's a virtual lock to be a starter in 2010.

LB Kawika Mitchell. Again, the Bills so sorely need depth here that Mitchell isn't going anywhere any time soon. Big and smart enough to play in a 4-3 or a 3-4. Reports indicate his knee will be healthy by the time the important off-season programs begin.

CB Terrence McGee. DBs are fairly easy to slot into any defensive scheme, particularly when they're as sound at tackling as McGee is. He's another player who recently got a contract extension as well.

CB Drayton Florence. The one player on this list that Nix is overtly aware of, as he was part of the team that drafted him in San Diego. Had a solid '09 season, and has the size and coverage ability to play well in any scheme. Is also quite easily the most physical DB on this list.

CB Leodis McKelvin. Even if he doesn't return to the lineup in a starting capacity, the Bills need a return man - Jackson can't wear as many hats next year as he did this year - and McKelvin has experience returning both kicks and punts at a high level. Contract status and upside cement his status.

S Jairus Byrd. Again, a no-brainer. I'm not sure Nix views him as an elite safety, but his ball skills and flair for the big play make him a huge asset to any defense. Might get better based solely on the fact that he has a chance to be healthy in 2010.

S Donte Whitner. Almost didn't include him on this list, but his versatility saves him for at least one more year - that's all he's got left on his contract, at any rate. New coaching staff will need to find a position for him and keep him there.

K Rian Lindell. Take a look around the league - solid kickers are very tough to find these days. Buffalo's got one, and he won't go anywhere any time soon.

P Brian Moorman. He's something of a cult hero in Buffalo, and a great team and community leader. Absolutely no reason for him to go anywhere else.

Depending on scheme, there are a few more players that could ultimately slip onto this list. And, obviously, some of these guys might drop off the list at some point as well. Right now, these 21 players are very safe bets to be in Buffalo next season; obviously, many more players currently on the roster will be here for training camp, because we're not going to go get 58 new players this off-season, but these guys are safe bets to be on the roster next year. Let your thoughts be known, Rumblers.