The New England Patriots have done a great job of building a roster without many obvious holes. It’s debatable if the team needs another between-the-tackles running back. The defense could use another edge defender to re-establish a four-man rotation and a three-down linebacker to team with Dont’a Hightower.

That’s about it. It’s seriously difficult to poke holes in the current Patriots roster, especially when Rex Burkhead has the makings of a good running back, Shea McClellin could theoretically step up on the edge as the fourth man in the rotation, and McClellin, Kyle Van Noy, and Elandon Roberts did a good job rotating next to Hightower in 2016.

The Patriots currently have the 10th most cap space in the NFL, per Over The Cap, and an opportunity to continue to develop the roster- beyond a surprise extension for CB Malcolm Butler.

Additional key veterans like WR Julian Edelman, LT Nate Solder, RB James White, RB Dion Lewis, EDGE Rob Ninkovich, LB Kyle Van Noy, ST Matthew Slater, ST Nate Ebner, and QB Jimmy Garoppolo will be unrestricted free agents after the 2017 season and could see new deals in the coming months as head coach Bill Belichick likes to sign key special teams players to extensions over the summer.

And then there are talented players like RB LeGarrette Blount, RB Brandon Bolden, and WR Michael Floyd that spent time with the Patriots, but have not yet been signed. Beyond the internal housekeeping, there are still interesting players still available in free agency that the Patriots could afford to bring into the fold.

Here are my favorite non-Patriots free agents.

30-year-old RB Jamaal Charles

The Patriots might not need a running back, but Charles has had just one visit so far- with the Seattle Seahawks- and they signed a different running back (RB Eddie Lacy). Charles has battled injuries over the past two seasons and is not a hot ticket item.

But that makes him an ideal buy-low candidate if he passes the necessary physical. From 2012-14, Charles played in 46 of 48 games and gained a ridiculous 5,049 yards from scrimmage and 39 touchdowns. At the age of 30, he might still have a year or two left in the tank, as he still managed to gain 595 yards from scrimmage and score 6 touchdowns over 8 injury-plagued games in 2015-16.

Charles would compete with Rex Burkhead to be the team’s leading rusher, but perhaps a rotation would benefit Charles at this stage in his career. Charles was released by the Chiefs and won’t affect compensatory pick calculations.

33-year-old EDGE Elvis Dumervil

Dumervil’s sacks have decreased from 17 to 6 to 3 over the past three seasons, but he can still generate a lot of pressure. The Baltimore Ravens used Dumervil on roughly 60% of snaps over the past four seasons and could fill in nicely for the Chris Long role as the third or fourth player in the pass rush rotation with 40-50% of the snaps.

Dumervil was released by the Ravens and won’t affect compensatory pick calculations.

800-year-old EDGE Dwight Freeney

Okay, Freeney is actually “just” 37 years old and he’s coming off a surprising productive season with the Atlanta Falcons. Freeney has earned the respect of head coach Bill Belichick of the years and could be a great veteran to have in the locker room.

Freeney still has a devastating spin move, which he used to destroy Patriots LT Nate Solder in the Super Bowl, and perhaps he could impart some of his knowledge to the young Trey Flowers. Freeney is a 30-40% snap contributor at this point in his career.

30-year-old LB DeAndre Levy

Levy was named Second Team All Pro in 2014 with the Detroit Lions and signed a 4-year extension. He then suffered a rash of injuries and played just 6 games over the next two years. Like Jamaal Charles, Levy is one of the best in the league at his position when healthy, but he’s a couple years removed from contributing.

Levy is a dominant coverage linebacker- he racked up 20 passes defended and 7 interceptions in 2013-14- and would pair nicely with Hightower in the middle of the Patriots defense. The Patriots would also get the inside scoop with Lions general Bob Quinn a former protege of Belichick.

The Lions released Levy to avoid paying $1.75 million guaranteed on the third day of the league year, so Levy won’t affect compensatory pick calculations.

32-year-old CB Leon Hall

Leon Hall spent the first nine years of his career with the Cincinnati Bengals before a one-year stint with the New York Giants in 2016. Hall fell out of favor with the Bengals after suffering two Achilles injuries and after Cincinnati invested a first round pick in a cornerback in 2012 (Dre Kirkpatrick), 2014 (Darqueze Dennard), and again in 2016 (William Jackson III) after parting ways with Hall.

The Patriots are looking to replace Logan Ryan in the slot and Hall is very experienced with that role and enjoys wearing multiple hats in a defense.

“I prefer it that way,” Hall said of the Giants using him on the outside, in the slot, as a dime back, and at safety, via Cincy Jungle. “I've always liked to do multiple things, which is part of the reason I like nickel so much. You get to do a whole plethora of things in coverages and blitzes, so being at dime is kind of the same idea as safety, which I played a little bit in Cincinnati or definitely practiced some of it. So it wasn't too out of the ordinary, but I like doing that kind of stuff.”

If the Patriots retain Malcolm Butler, then there won’t be a need for Hall, but he remains a veteran of note and interest.