Picking one free agent every team should sign this offseason

Free agency offers the chance for every NFL team to kick-start its roster improvements. Every franchise wants to excel in the draft and build its roster over the long term for minimal outlay, but free agency can fast-track that process and give teams proven NFL commodities -- if they are willing to pay for them.

The Dallas Cowboys arguably have the league's best offensive line because they threw draft resources at it for several seasons -- and hit on those draft picks -- but the Oakland Raiders came close to matching that with a free-agent spending spree, bringing in several key players to transform their line and offense overall.

With that in mind, here is one free agent -- unrestricted or restricted, from the list of every player who could make it to the market -- each NFL team should sign this offseason.

Note: Each player's position rank is based on PFF's grades, and we're not including re-signings -- only players switching teams. 

AFC EAST

Buffalo Bills

DeSean Jackson, WR | Position rank: 36th

Beyond Sammy Watkins, the Bills have gotten inconsistent production from their wide receivers, and Washington's Jackson provides another presence on the outside capable of getting behind the defense. Jackson led the league with 579 yards on deep passes while ranking second with 16 deep receptions. Perhaps Jackson is even more important for the Bills if Tyrod Taylor returns as their starting quarterback, as he throws one of the better deep balls in the league. Regardless of signal-caller, Jackson has enough juice to stretch the field and create big plays after the catch.

Miami Dolphins

Kevin Zeitler, G | Position rank: 7th

Don't be fooled by the emergence of running back Jay Ajayi, who led the league with 3.5 yards after contact per carry; the interior of the Dolphins' offensive line has had its struggles in the running game for a while. Enter Zeitler, who tied for ninth in the league with an 83.1 run-block grade last season. He's capable of creating movement at the line of scrimmage or locking onto defenders when on the move. Zeitler is also one of the better pass protectors on the interior, finishing fifth among guards, at 89.4. He allowed only one sack, three QB hits and 15 hurries on his 660 pass-blocking attempts for Cincinnati in 2016.