With the Patriots opening training camp on Thursday, here's one look at their top positional battles:

Center: Ryan Wendell vs. Bryan Stork

If Wendell performs like he did in 2012, he’ll be tough to beat. But if it’s more like 2013, then it could open the door for Stork, the fourth-round pick from Florida State. One other factor to consider: Wendell had a champion in former offensive line coach Dante Scarnecchia, but now he has to earn that type of trust from Scarnecchia’s replacement, Dave DeGuglielmo.

Right guard: Dan Connolly vs. Jon Halapio/Josh Kline/Marcus Cannon

Connolly has played plenty of good football for the Patriots, at both center and guard, and was another Scarnecchia favorite. But with a $3 million base salary that could be viewed as too rich by management, he could be pressed for the top job by Halapio (6th round) or others such as Kline or Cannon. The Patriots have some good competitive battles on the interior of the O-line.

3-technique defensive tackle: Tommy Kelly vs. Dominique Easley vs. Chris Jones

The 33-year-old Kelly is coming off a torn ACL that limited him to five games last season, and the Patriots have two up-and-comers in Easley (1st round) and Jones who could press him for the role playing next to Vince Wilfork.

Second-year receivers: Aaron Dobson vs. Kenbrell Thompkins vs. Josh Boyce

It is almost cliché at this point to note the "second-year jump," as players have a full year in the system and teams project improvement based on that, and more. Dobson (2nd round), Thompkins (undrafted) and Boyce (4th round) all flashed at times last season, but which one makes the biggest leap this year? That’s one of the bigger storylines in camp, because if none of them do, the Patriots could find themselves in the same situation as last year -- lacking enough potent weapons for Tom Brady.

Backup quarterback: Ryan Mallett vs. Jimmy Garoppolo

With Mallett entering the final year of his contract, the Patriots were looking ahead by selecting Garoppolo in the late second round (62nd overall). Mallett is the favorite to hold on to the No. 2 job for the third straight year, but no one saw what unfolded in 2009 -- undrafted rookie Brian Hoyer ousting 2008 third-round pick Kevin O’Connell for the No. 2 spot. So let’s see how the competition unfolds.

Safety: Duron Harmon vs. the field

When the Patriots released veteran Steve Gregory on Feb. 28, it opened up the starting safety spot next to Devin McCourty. Harmon, the 2013 third-round pick from Rutgers, is the leading candidate to fill the void after he played 36.9 percent of the defensive snaps last season as the top backup. His top competition comes from veteran Patrick Chung and third-year player Tavon Wilson.

Backup linebackers: Projected three spots for nine players.

This is a nitty-gritty battle that appeals most to die-hards. The starters are set with Jerod Mayo, Jamie Collins and Dont'a Hightower, and then it’s a question on who earns a projected three backup spots among a group that includes favorites Steve Beauharnais, James Anderson and Chris White, as well as Ja'Gared Davis, Darius Fleming, Josh Hull and Cameron Gordon, among others.

Long snapper: Danny Aiken vs. Tyler Ott.

Aiken has held the job the last three years, and he was re-signed to a modest one-year deal in the offseason as he was a restricted free agent. Ott, of Harvard, was one of the better prospects in what was considered a lighter snapper draft class. If the competition is close, Ott would seemingly have the edge based on having a cheaper, three-year contract.