NFL free agency primer: Vikings' No. 3 need is defensive tackle

NFL free agency begins next week, starting with the negotiating window on Monday and the opening bell for the 2018 league year at 3 p.m. Wednesday. Here's the third of a series assessing the Vikings' top five needs and how they could address them in free agency.

No. 5: Linebacker
No. 4: Tight end

The Vikings are looking to rotate some fresh legs into the defensive tackle spot alongside Linval Joseph next year. Tom Johnson played a career-high snap percentage nearing 70 in a career-high 15 starts. He'll be 34 entering next season and, if he re-signs in Minnesota, would ideally play more of a pass-rushing role, according to Mike Zimmer. The Vikings still had one of the NFL's best run defenses with Johnson and wouldn't necessarily be in a tough spot if they had to rely on him with a heavy role again. That's if the two sides can agree on a role and the price that comes with it. Defensive tackle Shamar Stephen has grown into a productive member of the Vikings rotation, making him a likely target for the team to re-sign.

Pending free agents: DT Tom Johnson (made $7 million over last 3 seasons), DT Shamar Stephen (coming off rookie contract)

Current roster: NT Linval Joseph ($8.05M), DT Jaleel Johnson ($724K), DT Caushaud Lyons ($555K),
*Sharrif Floyd's situation could affect the Vikings salary cap if his contract tolls after last year's slated $6.757 million cap hit, which is currently the topic of another grievance after the Vikings decided to instead pay him a $2 million base salary last season.

Current money invested: $28.1 million, 10th-most among NFL defensive lines, according to OverTheCap.com.

DT David Irving (Cowboys) — The restricted free agent reportedly might get the first-round tender from the Cowboys, meaning a team would have to surrender a first-round pick on top of whatever offer sheet the original team isn't willing to match. The 24-year-old Irving missed eight games between a suspension and concussion, but accrued seven sacks in the eight games he played.

DT Dontari Poe (Falcons) — Poe, 27, bounced back in Atlanta after sputtering out with the Chiefs. The Falcons run defense improved from 17th to ninth after signing Poe, who figures to land a long-term deal as a team's starting nose tackle.

DL Sheldon Richardson (Seahawks) — The Seahawks sounded open to re-signing Richardson, the 27-year-old former first-round pick who has just 2.5 sacks in the last two seasons. Richardson is still young enough where teams will take a chance on the 6-3, 295-pound talent.

DL DaQuan Jones (Titans) — Jones came on during his fourth season in Tennessee, compiling a career-high 3.5 sacks to pair with a reputation as a solid run defender. He could be worth a look after the Vikings took a swing on a different 3-4 defensive end project last year in Datone Jones.

DT Haloti Ngata (Lions) — The 34-year-old Ngata might not be the pass-rushing threat he once was, but he could still help a defensive line on first and second down. Buyer will have to beware the oft-injured Ngata is coming off torn biceps that ended last season.

DT Jay Bromley (Giants) — Bromley (6-3, 285 pounds) was talented enough to be a third-round pick by the Giants in 2014, but he hasn't lived up to expectations with two career sacks. He turns 26 in May and is still young enough to be molded.

Also keep an eye on: DL Denico Autry (Raiders), DT Kyle Williams (Bills) and DT Dominique Easley (Rams).