While it remains to be seen how exactly David Harris will fit into Bill Belichick and Matt Patricia's defensive scheme, he is a known commodity in terms of his instincts and football IQ.
Will those traits be enough to earn him a key role immediately? And with whom will he be competing for time alongside Dont'a Hightower?
Let's have a look at what the Patriots have at the linebacker spot now that Harris is in the mix.
Dont'a Hightower, 6-foot-3, 265 pounds: The signal-caller for the Patriots defense and a first-time captain last season, Hightower opted to re-sign with the team as an unrestricted free agent for a deal worth $35.5 million over four years. Hightower is an every-down player who is critical to the team's ability to stop the run. He's also improved significantly in coverage over the course of his career to the point where he's one of the best at his position at limiting yards after the catch. And when he's asked to rush the passer, he's among the game's most efficient in that regard. His strip-sack of Matt Ryan in the fourth quarter of Super Bowl LI was the turning point in New England's improbable comeback win.
David Harris, 6-foot-2, 250 pounds: Among the former Jet's best qualities is his durability, as he has missed just one regular-season game (it came in 2016) in the last eight seasons. The 33-year-old's percentage of snaps played between 2009 and 2015 reads as follows, according to Pro Football Focus: 94.8 percent, 97.0, 93.2, 99.4, 99.8, 99.4, 92.2. Harris possesses the size the Patriots often look for in their middle linebackers, and he has experience serving as the primary communicator for a defense, which Belichick and Patricia would likely value. In 2014, Harris tied his career-high in sacks with 5.5. Per PFF he was fifth among linebackers last season in terms of yards allowed per coverage snap (0.73).
Elandon Roberts, 6-feet, 235 pounds: Going into his second year out of the University of Houston, Roberts made eye-opening plays as a rookie in the running game, using his strength and anticipation to occasionally overpower linemen. With a full NFL offseason under his belt, Roberts would land in the category of second-year players who could make a "leap" headed into 2017. He played 35 percent of defensive snaps for the Patriots last year.
Kyle Van Noy, 6-foot-3, 243 pounds: Van Noy's relatively unique combination of size and athleticism makes him another versatile piece for Belichick and Patricia. After arriving to the Patriots via trade mid-season last year, he was frequently used in coverage in the middle of the field and deployed as a blitzer. He had 34 tackles in 10 games with the Patriots (including playoffs) and recorded a half-sack in the Super Bowl.
Shea McClellin, 6-foot-3, 250 pounds: After Hightower and Jamie Collins, it was Shea McClellin who played more snaps in 2016 than any other Patriots linebacker (382). A versatile option, McClellin was spotted often playing opposite Rob Ninkovich as an end-of-the-line pass-rusher during OTAs and minicamp this spring. He has experience playing off-the-line as well, but seemed to be more of a fill-in option in that role last season.
Jonathan Freeny, 6-foot-2, 255 pounds: Freeny saw 453 defensive snaps in 2015, which was more than any other Patriots linebacker after Hightower and Collins. He spent most of 2016 on injured reserve with a shoulder injury, but returned to participate in practices this spring -- albeit while wearing a red non-contact jersey. An experienced special-teamer, Freeny could be one of the team's top linebackers in the kicking game if healthy. He signed a two-year extension with the Patriots last August.
Harvey Langi, 6-foot-2, 252 pounds: The Patriots signed Langi to an undrafted free agent deal that reportedly guaranteed him $115,000 -- more money than any other undrafted rookie in this year's class. He played both as an edge defender and off the line at BYU and may need to prove to the team that he has value in the kicking game in order to make the roster. Fellow undrafted rookie 'backer Brooks Ellis and 2016 practice-squadder Trevor Bates seem to fall into a similar category.