The Bills head into the preseason with their deepest and most talented roster in years as they look to advance to the postseason for the first time since 1999.

There are still a few questions that remain, however, as they begin the exhibition season. The battles for the starting left tackle and No. 2 QB jobs are wide open, and Buffalo suddenly has an interesting competition at strong side linebacker. The Bills also are counting on two youngsters to step up in the secondary.

Here’s a look at Buffalo’s most pressing questions heading into preseason action: 

1. Who will start at LT? In all likelihood, the Bills would prefer to have rookie Cordy Glenn win the starting left tackle job. The team drafted Glenn in the second round to become their left tackle of the present and the future, and like his upside. But he’s had some struggles at his first NFL training camp and may not be ready to start. Assuming RT Erik Pears is healthy in time for the opener, it looks like Chris Hairston could start the year on the blind side (if he isn’t needed on the right side). The Bills offense survived when Hairston was forced to start seven games last season, but he hasn’t exactly stood out at camp. Preseason games could go a long way in determining this battle.

2. Will Vince Young or Tyler Thigpen step up? Ryan Fitzpatrick is the unquestioned starter at QB, but the primary backup position remains up for grabs. Buffalo signed Vince Young to a one-year deal this offseason, but he’s had his share of struggles as he tries to pick up Chan Gailey’s offense. Thigpen, the incumbent, has also had issues with his accuracy, though he seemed to show some improvement at Buffalo’s most recent camp practices. As with left tackle, preseason games could determine the winner here.

3. Is Arthur Moats the favorite at SLB? The strong side linebacker job wasn’t considered to be open heading into training camp. Buffalo re-signed Kirk Morrison to take that role, but defensive coordinator Dave Wannstedt revealed Tuesday that Arthur Moats was probably a “nudge” ahead of Morrison at the moment. Moats has been receiving an increased number of reps with the first team as of late. Both players are set to receive equal reps in preseason action, but it now appears to be Moats’ job to lose.

4. Are Buffalo’s youngsters at CB ready to contribute? First-round pick Stephon Gilmore has been a standout at camp and is already the team’s No. 1 CB. Still, it remains to be seen how he’ll react in game action. Second-year pro Aaron Williams, a second-round pick from one year ago, has struggled with his consistency at camp. Both are expected to benefit from Buffalo’s improved pass rush but are unproven commodities at this point in time.

For more updates on the Bills follow correspondent Mark Ludwiczak on Twitter @CBSSportsNFLBUF and @MarkLud12.