Another question to the secondary is who will play next to Devin McCourty in the defensive backfield. While Patrick Chung won the job by default last camp and parlayed that into a solid season and a 3-year contract extension. Even with that, I don't believe he's guaranteed a starting spot. With the CB situation in flux, there is likely a larger need for two deep safeties instead of one. Over his career, Chung hasn't proven to be reliable in that capacity which could open up an opportunity for Duron Harmon to take over.
The one thing I do like about Harmon as the second safety is it allows the Patriots to be more versatile in their coverage looks. It allows McCourty to play down into slot to match up against tight ends in four and five defensive back personnel groupings. With Charles Clay and Jordan Cameron in the division, expect to see that match up a lot. At the same time, while Harmon makes the pass defense better he also makes the run defense weaker. Harmon and McCourty aren't best suited playing in the box. That's where Chung excels. So this might not be a one player plays most of the snaps situation.
Contestants: Duron Harmon, Patrick Chung, Tavon Wilson, Jordan Richards (R)
Projected Winner: Patrick Chung and Duron Harmon
So how is it that both contestants win? It comes down to match ups and personnel. When the Patriots go four defensive backs or play against run-heavy teams, Chung would likely get the nod because of his presence in the box. Then when the Patriots substitute to their nickel package, they could substitute Harmon in for Chung. Then when the Patriots switch to dime defense, Chung would then come back on the field as the 6th defensive back.
Since the Patriots' three divisional foes depend heavily on the ground game, Chung will be getting more snaps. Other games I expect to see a lot of snaps for Chung are against Philadelphia, Dallas, and Houston. Against Denver, Indianapolis, and the NY Giants I would expect to see more snaps for Harmon than Chung because those teams use more spread formations and pass out of them. Injuries can certainly change that, whether the Patriots or their opponents suffer through them. I believe at the end of the season that both players will be on the field for a significant chunk of snaps (at least 45% each).