With their deepest roster in years, the Bills head to training camp with only a few key position battles. Here are the top three competitions to watch at camp:

WR -- Donald Jones vs. Derek Hagan vs. Marcus Easley. The Bills are set at one wide receiver position with top wideout Stevie Johnson. The other outside role, however, is completely wide open. Jones, the incumbent, had a strong spring and has a leg up on his competition -- but he also operated out of the slot for most of June. Will that affect his position moving forward? Hagan, picked up off waivers last November, hopes to have finally found a home in Buffalo. He has good speed for a big man and quietly had a nice spring. Easley is the wild card; the former fourth-round pick missed each of his first two seasons due to injury but has an intriguing combination of size and speed. Can he finally stay healthy?

Backup QB -- Vince Young vs. Tyler Thigpen. The Bills added some insurance at QB this offseason by signing Young, and the No. 2 quarterback job is expected to be his to lose. Neither QB impressed in the spring, however, so things could change at camp. Thigpen performed well under Gailey in Kansas City in 2008, throwing 18 touchdowns in 11 starts, but he has yet to resemble that quarterback while in a Bills uniform. Accuracy has been a major problem for Thigpen. Young also has struggled with his accuracy, but he clearly has the upper hand.

LT -- Cordy Glenn vs. Chris Hairston. The Bills have maintained all along that Glenn is a left tackle, not a guard, in the NFL -- and they’re depending on him to prove them right as a rookie. Buffalo selected Glenn in the second round with hopes that he could instantly fill the void left by Demetress Bell’s departure. He received all of the first-team reps at left tackle in the spring, and it’s obvious that the Bills want him to step up and win the job. But Glenn is a rookie and will need some time to adjust to the NFL, leaving the door open for Hairston. A fourth-round pick one year ago, Hairston started seven games in 2011 but struggled greatly in the spring. Still, this battle could be closer than most observers think due to Glenn’s inexperience.

For more updates, follow Bills correspondent Mark Ludwiczak @CBSSportsNFLBUF and @MarkLud12.