We asked our three Patriots reporters to tell us which positional battles they’re looking forward to watch play out at training camp, which begins Thursday at Gillette Stadium:

Backup quarterback: Hoyer vs. Mallett

The preseason is when we get a chance to see the strength of the Tom Brady insurance policy.

No, it’s not the most exciting positional battle to select, but by the time the Patriots play their four preseason games, chances are Hoyer and Mallett will have played more total snaps than Brady. The preseason is the season for backup quarterbacks.

And it makes sense, because this is the one time when they can have extended action and react to the myriad of situations that come up in a game. As much as they work in practice, what happens in a game setting can’t be fully duplicated. This is their time to accumulate good tape.

Hoyer, in his fourth season out of Michigan State, has shown flashes of solid play and with a strong preseason could position himself for a big payday on the open market in 2013. He seems to have great command of the huddle.

Mallett, a highly touted third-round pick in 2011, has desirable physical traits (e.g. strong arm) and an impressive college resume. With three years remaining on his contract, he’s positioned to eventually graduate into the No. 2 role.

Could it be as soon as this year?

That is one of the questions to be answered at camp.

At first glance, the Patriots appear to have one of the most stocked quarterback depth charts in the NFL. The progress of Hoyer and Mallett, and who fits where on the depth chart, will be worthy of monitoring. -- Mike Reiss

Offensive line: Center/guard shuffle

On paper, this position would seem to be settled. Dan Koppen has been the Patriots’ center since 2003, while left guard Logan Mankins and right guard Brian Waters were both named Pro Bowl starters last season.

But something isn’t quite right here.

Mankins’ status still isn’t known for the start of training camp this week, or beyond. When he’s healthy, he will be the hands-down starter at left guard. But until then, there will be uncertainty at that spot.

Affecting what happens at left guard will be both the center and right guard positions. Waters still hasn’t made an official indication of whether he will return to play this season, and even if he does, one has to wonder what effect his excused absence from organized team activities will have on the 35-year-old’s standing with the team and with other players.

What really makes this position curious was the team’s decision to re-sign Dan Connolly to a three-year, $9.7 million deal, bring back Koppen on a two-year, $6 million deal, and also ink Robert Gallery to a free-agent contract.

Add in dependable reserve and spot starter Ryan Wendell, and it’s too many players, too much money, for too few spots.

How this position will play out in training camp will be a significant storyline. Will Waters report to camp and still hold down the right guard job? Who will emerge at center: Connolly or Koppen? If it’s Connolly, is Koppen’s roster spot secure? Where does Gallery fit in?

Again, much of this depends on the health of Mankins. But if you’re looking for intrigue in New England this preseason, you’ll find it in the trenches. -- Mike Rodak

Defensive end: At least five players for two starting spots

Where first-rounder Chandler Jones fits on the defensive line depth chart is something to watch for this summer. AP Photo/Charles Krupa

It’s not uncommon for positional battles to focus on two players vying for one spot, but in the case of the defensive end position for the Patriots, I foresee at least five players vying for two starting roles: Jonathan Fanene, Trevor Scott, Chandler Jones, Jake Bequette and Rob Ninkovich.

Given the number of sub package defense the team projects to play, it’s likely that all five of these players will accrue a high total of snaps as the team rolls through its depth to keep the legs fresh and pass rushing pursuit at full-bore. But when the team lines up in its base 4-3 defense (all signs point to a reliance on a four man front in 2012), which two players will bookend the defensive line?

Scott, Ninkovich and Fanene are all proven veteran players, with Scott and Fanene in particular having experience at the end position (Ninkovich has had his most success as a 3-4 outside linebacker). Jones adds an element of dynamic athleticism, while Bequette was praised in some pre-draft scouting reports for his polish. In this group of five players, the Patriots appear to have a blend of toughness, explosion and capable run defenders and pass rushers.

The team surrendered 4.6 yards per carry and generated 40 sacks in 2011; if this new group of defensive ends can contribute on the field what it appears capable of on paper, the Patriots could be in for a beefed up defense. In the meantime, watching this position battle sort itself out should prove worthwhile throughout training camp.

Two bonus names to keep an eye on are Brandon Deaderick and Jermaine Cunningham, who each enter a pivotal third year of their career. -- Field Yates