As the Packers head into their third training camp under Mike McCarthy, there are fewer of the 53 roster spots in question because of the number of young players who have established themselves over the past couple of seasons. But that doesn't mean there aren't plenty of positional battles and other competitions worth watching, and here are just a few:

Offensive guard:The left guard spot is an open competition between third-year pro Daryn Colledge, who has started 28 games in two seasons, and second-year man Allen Barbre, who played (but did not start) in seven games as a rookie.

Colledge obviously has experience on his side, and though he's had his ups and downs through his first two seasons, he has always responded well when his job has been challenged or thrown open to competition. Meanwhile, Barbre came in as a fourth-round draft project from Division II Missouri Southern but has made the type of improvement through his rookie season and into his second that the coaches expected. May the best man win.

Strong-side linebacker:Brady Poppinga has been the starter here the past two seasons, since returning from a knee injury at the end of his rookie 2005 campaign. The team's lone signing during free agency was former St. Louis starter Brandon Chillar, who will go head-to-head with Poppinga for the starting spot alongside Nick Barnett and A.J. Hawk.

Poppinga, who signed a four-year contract extension earlier this week, stood out defending the run late last season, particularly in the NFC Championship Game, with some hard hits. Chillar has a reputation as a quality cover guy against tight ends. Both players have handled the competition professionally thus far, and it's a win-win situation for the Packers. No matter who emerges with the starting job, there's a quality, experienced backup ready to step in at a moment's notice if the situation warrants it. And whoever's not starting can help on special teams too.

Safety:Starters Nick Collins and Atari Bigby are considered young, ascending players with their best play still ahead of them, but second-year pro Aaron Rouse made a big splash during three starts last season for an injured Collins, picking off two passes. Collins is the most experienced of the group, while Bigby was playing his best football down the stretch and in the playoffs last season, intercepting four passes in December and forcing a key fumble in the playoff victory over Seattle.

With the "strong" and "free" safety spots interchangeable in the Packers' defense, this becomes three players vying for two starting jobs, and the end result could be any of the three possible combinations.

Wide receiver:Each of the last two years, a rookie receiver has come in and gotten noticed quickly. In 2006, it was the polished Greg Jennings. Last year, it was the physical, strong James Jones. This year, the highly touted rookie receiver is second-round draft choice Jordy Nelson from Kansas State.

{sportsad300}Can Nelson turn heads in a similar fashion in his first camp? If he does, he's likely to push Jones for the No. 3 receiver spot. No matter how the pecking order shakes out, the offense looks to have plenty of good hands with these three rising stars, plus No. 1 Donald Driver and a productive veteran reserve in Ruvell Martin.

Long snapper:For the first time since the team's last trip to the Super Bowl, the Packers will have a new long snapper in 2008 with the retirement of Rob Davis. Thomas Gafford, who competed with Davis for the job during training camp in 2006, had the early edge in the competition, but non-drafted rookie J.J. Jansen made a strong push toward the end of OTAs and during the June mini-camp.

This is one of those positions where guys only get noticed when they make mistakes, and any mistake will be magnified with the job on the line.

Sleepers:Every year one or two players surprise everyone by going from the bottom of the depth chart to the 53-man roster by the end of training camp. Two years ago it was defensive end Jason Hunter, tight end Tory Humphrey and receiver Ruvell Martin. Then last year it was cornerback Tramon Williams and defensive tackle Daniel Muir.

With the current state of the roster and the team coming off such a great season, the chances for "sleepers" are diminishing. But you never know whether an injury or breakout performance in a preseason game changes the landscape.

Can Kregg Lumpkin do enough to steal a roster spot at running back from a veteran player? Will one of the non-drafted free agent tight ends emerge as a bona fide prospect? Will Johnny Quinn continue his impressive work thus far and make a push in the receiving corps? We'll soon find out.