The Patriots top 3 linebackers are Jerod Mayo, Dont'a Hightower, and Jamie Collins. On paper, that trio is arguably the best trio of linebackers in the NFL. In the grand scheme of things, that's not nearly as important because as we saw the last two years that 1 major injury can really wreck the initial plan. At a position that is physically demanding, injuries are going to happen. You can't predict injuries, but you certainly can prepare your team to be able to weather through that.
Which brings up the topic of linebacker depth. One of the most common phrases in terms of a group of people working to achieve the same goal is, "You're only as good as your weakest link". If an injury should strike and one of the top 3 linebackers misses time during the season (all 3 missed at least 1 game in the 2014 season), the team needs to have readily available options to be able to at least be serviceable enough for the Patriots defense to still do 90% of what they would do with their normal starters in. In addition, these players would need to be able to perform on at least 2 Special Teams units, if not all 4.
Contestants: James Morris, Dane Fletcher, Dekoda Watson, Deontae Skinner, Matthew Wells, Darius Fleming
In terms of experience, Dane Fletcher has seen the most time in the Patriots system. After making it as an UDFA in 2010, Fletcher was a valuable backup to the team for four years before signing a 1-year deal with the Tampa Bay Buccaneers. Fletcher doesn't stand out at any particular aspect, but can do everything well enough that the Patriots don't have to completely change schemes. Another player with a very good chance of making it is over Iowa linebacker James Morris. He was having an excellent 2014 camp from all reports and had a shot to make the roster before his season prematurely ended at the end of preseason. He's going to have to prove that he's healthy and still produce at the same level as last year's camp to make it. I do believe he is a future starter, whether it's in New England or somewhere else.
Two players from that list will likely make the team if Belichick carries 5 linebackers on the active roster and he may opt to carry 6 depending on how camp rolls out. Another player with an intriguing skill set is rookie Matt Wells. Not many people knew about Wells in the pre-draft process, but after the Patriots made the selection I definitely liked the pick. Wells is a linebacker that can cover like a defensive back, even outperforming 1st rd pick Shaq Thompson according to Pro Football Focus. Belichick has always been looking for a Safety-Linebacker hybrid for his sub packages, and this could be the guy. At the end of the day, Wells is a rookie and will need to show off his 4.44 speed on special teams and covering tight ends.
Skinner and Watson have NFL experience and can contribute on Special Teams. Skinner was a solid backup, picking up for Jamie Collins and Dont'a Hightower when they battled injuries early in the 2014 season. He became phased out of the game plan and off the roster when the Patriots traded for both Akeem Ayers and Jonathan Casillas. Now in his second year in the system, it's make or break for him. He's still practice squad eligible and managed to sneak onto there when the Patriots waived him midseason.
Projected Winners: James Morris, Matthew Wells, Darius Fleming
I'm going with 6 linebackers on the active roster. Depending on how the other positions take care of themselves, the Patriots might not be able to carry that many. Morris and Fletcher can back up all 3 linebacker positions in the defense while also playing inside in 3-4 looks. Wells projects to be a sub player and a core special teamer (4-unit), but might not see the field against run-heavy opponents (e.g. Dallas Cowboys). With Mayo and Hightower battling back from major knee and shoulder injuries, the guys playing behind them could be the difference for the Patriots in 2015.