Buffalo Bills' Defensive Tackle Depth Chart Lacks Clarity

As we approach 2012 Buffalo Bills training camp, there are some impending positional battles that are easy to define, and others that are much more difficult. The backup quarterback job would fit the former description, as we're reasonably sure that the job will go to one of Tyler Thigpen or Vince Young. Things are not as clear-cut at defensive tackle, which is the position that's most difficult to get a read on right now for the Bills.

Mercifully, there is definition at the top of the depth chart, where we know that Kyle Williams and Marcell Dareus are the starters, and the players that will get the most playing time this season. Beyond that (potentially dynamic) duo, however, there are a lot of options, and far more questions than answers a month removed from the start of camp at St. John Fisher.

For starters, does anyone - the Bills included - really know at which position Spencer Johnson will be playing next season?

While the Bills were patching together some semblance of a defense in 2011, Johnson spent the bulk of his time playing at defensive end when the team used its nickel and dime packages. The 6'3", 304-pound veteran is a much better fit inside at defensive tackle, however - and the thought was that with the Bills switching back to the 4-3 under Dave Wannstedt, Johnson would again play defensive tackle. That has not strictly been the case, however, as Johnson will reportedly keep playing both positions for the foreseeable future.

In the end, where Johnson lines up could be relevant to where the Bills seek to bolster depth at the back end of their defensive line depth chart. The other option: calling Johnson a 'tweener, making no delineation between ends and tackles, and simply taking the two or three best players to round out the depth chart.

Johnson is the seventh defensive lineman on the team that, assuming full health, seems destined for a spot on the 53-man roster (joining Dareus and Williams at defensive tackle, along with Mario Williams, Mark Anderson, Chris Kelsay and Shawne Merriman at end). That leaves at least one spot - but perhaps two, or even three if the team likes its depth enough - for the remaining players to fight for roster space.

There are a lot of competitors for those spots.

Dwan Edwards, an eight-year NFL veteran and two-year starter for the Bills, belongs in that conversation. So, too, do 2010 draft picks Torell Troup (second round) and Alex Carrington (third). Then there's Kellen Heard, who showed signs of being able to contribute late in 2011 while filling in for the injured Troup.

That's four competitors for what will likely turn out to be one or two roster spots. Troup is coming off of a back injury, and though he's expected to be fully healthy by training camp, the jury is still out on whether or not he can become the productive contributor that the team intended when they made him a second-round pick two years ago. Carrington got some valuable starting experience late in the 2011 season, but did not have a lot of production to show for it - and he'll be moving full-time to tackle this year after being drafted to play 3-4 defensive end. Wannstedt has spoken highly of Edwards this off-season, and he did set a career high with 2.5 sacks last season. Heard showed improvement through the course of last season, and ended the year with a two-sack performance in a loss to New England.

Which of this quartet of players do you believe faces the longest odds of making the team this year, Bills fans? And do you see a clear front-runner in the group?