Rookies Ja'Whaun Bentley, Christian Sam are wild cards in Patriots' LB mix

In the lead-up to New England Patriots training camp, with the first public practice scheduled for July 26, it is timely to review each position on the roster with our annual "roster locks" series. After highlighting the running backs, wide receivers and defensive ends, let's move on to the linebackers:

Locks: Dont'a Hightower, Kyle Van Noy

On the bubble: Elandon Roberts, Marquis Flowers, Ja'Whaun Bentley, Christian Sam, Harvey Langi, Nicholas Grigsby

Explaining the locks: This is pretty straightforward after the Patriots didn't sign a linebacker in free agency or select a player at the position in the draft until the fifth round (Bentley) and sixth round (Sam). Hightower is a two-time captain who is entering the second year of a four-year, $33.5 million contract, and his presence immediately upgrades the unit after he missed the second half of 2017 with a torn pectoral muscle. Meanwhile, Van Noy had signed a two-year, $11.75 million extension last year, which reflects how the Patriots view him as a significant part of their future plans. In the 4-2-5 nickel defense that the Patriots often play, a Hightower/Van Noy combination would be the projected pairing at the off-the-line linebacker position.

Roster management: The Patriots kept six linebackers on their initial 53-man roster last season (not including Shea McClellin, who was quickly shifted to injured reserve), and special teams are usually a big consideration for the final few spots. That is a big part of Flowers' value to the club, and his athleticism and speed also showed up last year as a dime linebacker. So he has a good shot to stick around, while Grigsby is similar to former Patriots veteran Tracy White, a speedy core special-teamer who played for the club from 2010 to 2012, mostly on fourth down. If Grigsby makes the roster, it will be because he proved to be indispensable in the kicking game. Roberts was the third linebacker last season and is at his best playing downhill against the run and as a blitzer, and he could be facing competition from Bentley, of Purdue, for that type of middle linebacker/base defense type of role this year. Sam, the sixth-round pick from Arizona State, projects as more of a weakside linebacker and his work on special teams ultimately will determine if he makes it. Langi is a player who showed up once the pads came on last year in training camp, as he initiated contact and put forth some notable work in pass-rush drills.

Stat of note: Hightower, whose health is critical to the defense in part because he plays a central role in the overall communication, played 76.7 percent of the defensive snaps in 2014, followed by 54.2 in 2015, 67.9 in 2016, and 22.3 in 2017.

One thing to watch for in camp: Breaking through as a rookie with the Patriots is a challenge at any position, but linebacker is closer to the top of the learning curve in terms of everything that comes with it, which is why keeping tabs on Bentley and Sam is a worthy time investment. Specifically, when the linebackers blitz against running backs, Bentley is the type of player whose pads pop because of the force with which he plays.