Everyone knew the Vikings roster was going to go through major changes this offseason because of the number of veteran players they had clogging up the salary cap, but it has still been incredible to see so many players leave the club in the past few weeks.

As of Wednesday, the list of players gone included Mackensie Alexander, Stefon Diggs, Dakota Dozier, Everson Griffen, Linval Joseph, Josh Kline, Jayron Kearse, Xavier Rhodes, Andrew Sendejo, Marcus Sherels, Laquon Treadwell, Trae Waynes and Stephen Weatherly.

It's hard to believe the team has lost so many quality players in such a short time. And it also shows how quickly the team is going to have to rebuild for next season.

Pro Football Focus ran a list of the NFL teams hit hardest by free-agent losses this season, and the Vikings ranked 22nd, near the middle of the pack.

They gave the Vikings a grade of "poor" in free agency and wrote that, "The best move the Minnesota Vikings made was cutting Xavier Rhodes. He's been a liability in coverage, ranking 112th of 119 in PFF coverage grade and allowing an incredibly high 83.5% catch rate. The cornerback position outside of Rhodes was nothing special, either, as the unit ranked 27th in PFF coverage grade. The top two corners on the roster were Waynes and Alexander, and both of them are now Cincinnati Bengals, leaving the position depleted."

Even with the loss of standout wide receiver Diggs, the biggest concern is on defense. But Vikings coaches have long believed they have some young defensive linemen who are ready for more playing time. That group includes Jaleel Johnson, Jalyn Holmes, Ifeadi Odenigbo and Shamar Stephen.

Last season Johnson recorded 29 tackles, 3½ sacks and 5½ tackles for loss.

Odenigbo was the biggest surprise of the season with seven sacks and eight tackles for loss to go along with 23 overall tackles.

Stephen had 21 tackles, a sack, a forced fumble and a fumble recovery.

Holmes had four tackles, but the 2018 fourth-round pick is viewed by the Vikings staff as the kind of physical player who could make a big leap.

But while there are defensive linemen who the Vikings believe can replace the production of veterans such as Joseph and Weatherly, the defensive backs are a different story.

Jones' tough task

The Vikings' decision to move on from defensive backs coach Jerry Gray at the end of the season couldn't have been an easy one, after him being with the club for all of Mike Zimmer's tenure.

Gray landed with the Packers after the Vikings hired Daronte Jones to replace him.

Jones had spent the past two seasons with the Bengals and the two seasons before that with the Dolphins.

But you have to wonder if the reason the Vikings moved on from Gray at this point is because they knew they were going to be bringing in a basically brand-new defensive backfield and wanted a different coach to work with that group going forward.

Jones said at his introductory news conference in February that he was looking forward to working with Zimmer, who is an elite defensive backs coach.

"It's no secret he's a secondary guy, his secondaries in the past have had tremendous success and his defense as a whole," Jones said. "So just learning from a mind like that and all of the experience he has, learning how detailed he has been, how he has focused on the progression and the teaching of individual players and working on crafting their techniques, I can definitely learn from that."

Looking back to the Vikings' final game last season, cornerbacks Rhodes and Waynes played 69 of 71 snaps on defense and Sendejo took 22 of 71 snaps at safety. All three of those players will not be on the club next season.

One positive for Jones and the Vikings staff is that safeties Anthony Harris and Harrison Smith will probably both be back, although it is rumored that Harris could be had for a draft pick. Those two players took 100% of the snaps in the Vikings' final game of the 2019 season.

But who else will fill out the defensive backs?

Mike Hughes had a great rookie season but also dealt with a severe neck injury and Holton Hill dealt with a suspension before appearing in eight games.

Loss of pro days

Before the shutdown of NCAA sports because of the coronavirus pandemic, the Vikings had plans to attend several college pro days around the country.

The big question around the NFL now is how the league will approach the NFL draft, currently scheduled to take place from April 23-25 with no public attendance.

Some general managers are wondering if they will be able to have enough data on all the players in the draft during this unique offseason.

General Manager Rick Spielman recently explained why those pro days are so important compared to just attending the NFL combine.

"I know when we go out to pro days, our coaches can get their hands on [players], particularly running drills. A lot of times you'll carve them out and maybe spend some extra time on the side, seeing if they can do a particular technique that I can ask them to do," Spielman said. "Of course you get an opportunity at pro days … just going out there and especially the juniors that came out, talking to all your sources in those buildings and the relationships you have with those people to get as much background on them as you can.

"When you go out and do those pro days, not only do you work them out but you're doing some more gathering of information and making sure you're getting all of the I's dotted and the T's crossed before we get back into our final meetings in April."

It's hard to imagine how much harder the draft will be this year for all of the NFL teams without having that pro day information.

And for players such as Gophers wide receiver Tyler Johnson, who decided not to work out at the combine because he wanted to showcase himself at University of Minnesota pro day, you have to hope it doesn't hurt their draft stock.

And speaking of the Gophers, ESPN ran a list of the top-10 players at each position heading into the NFL draft. Gophers safety Antoine Winfield Jr. ranked No. 1 at safety while inside linebacker Kamal Martin ranked No. 9.

Sid Hartman can be heard on WCCO AM-830 at 8:40 a.m. Monday and Friday, 2 p.m. Friday and 10:30 a.m. Sunday. • shartman@startribune.com