The Vikings filled their biggest need with an even bigger human being, landing one of the top two nose tackles less than 90 minutes into the NFL's free-agency signing period on Tuesday afternoon.

Linval Joseph, a conservatively-listed 6-4, 328-pounder who was bench-pressing 415 pounds as a high school junior in Florida, leaves the Giants, where he was the 46th overall draft pick in 2010, for the Vikings, where he will be paired next to Sharrif Floyd, the 23rd overall pick a year ago. Floyd is 21, while Joseph, who signed for $31.5 million over five years, is 25.

Throw in 26-year-old defensive end Everson Griffen, who was re-signed to take Jared Allen's role at right end, and an aging defensive line that started three 30-somethings a year ago now has three under 27.

"It's pretty crazy, man," said starting left end Brian Robison, a soon-to-be 31-year-old former fourth-round pick from 2007. "It seems like everything went by in a blink of an eye. Now, I'm sitting looking around and I'm kind of the old guy in the room. It'll be interesting, but I plan on taking that leadership role on with all these young guys around."

Robison said he doesn't know much about Joseph, who, despite his youth, has started 46 of 48 games the past three years, missing only one game because of an ankle sprain a year ago. The Vikings haven't had a true nose tackle in top form since Pat Williams' last dominant season in 2009.

"All I know is that was one of the things we definitely needed was a nose tackle," Robison said. "Hopefully, [Joseph] fills that void."

Giants defensive tackle Linval Joseph has nine sacks in three years, but his specialty is stopping the run.

With Joseph, Griffen and quarterback Matt Cassel locked up, the Vikings' top need now is cornerback, with left guard and linebacker also a concern. Two of the top corners in free agency — Tennessee's Alterraun Verner and Indianapolis' Vontae Davis — were signed on Tuesday. Verner went to Tampa Bay while Davis re-signed with the Colts.

But even with a serious need at cornerback, nose tackle still was the most pressing concern considering new coach Mike Zimmer's reliance on massive yet agile nose tackles and the fact that the only defensive tackles on the roster were Floyd, Chase Baker and Kheeston Randall, the former Bengals backup nose tackle who was signed on Jan. 22.

In the opening moments of free agency, some worried that the Vikings had been shut out of their intended target when the Falcons jumped on Miami's Paul Soliai, giving him a five-year, $32 million deal. But it was Joseph whom the Vikings had been pursuing as the kind of massive run stopper who also has shown an ability to rush the passer with nine sacks in three years, including two in one game against the Cowboys' Tony Romo in 2012.

Robison viewed the Joseph signing as bittersweet, realizing that it probably was the final move signifying the end of Kevin Williams' potential Hall of Fame run with the Vikings. After all, the Vikings gave Robison $28 million over four years late last year, Griffen $42.5 million over five years on Saturday and then $31.5 more to Joseph on Tuesday.

"You wish everybody could play their whole careers together, but that's just not the way this business works out," Robison said. "I wish Kevin the best. He's had a heck of a career.

"I haven't been told anything official, but you look at the money that's being spread around. There are a lot of other positions that need to be addressed and we can't put the whole pot in the D-line, so you just kind of get the feeling that we're parting ways with Kevin."

Robison also gave no indication that Griffen's more lucrative contract would be a problem for him. Robison, a former backup who went on to prove himself as a regular starter, got $14 million guaranteed. Griffen, who has had one career start, got $20 million guaranteed.

"Everson has done a lot of great things and is a guy who has really grown up and matured a lot over the years," Robison said. "He's definitely a guy who has helped us win. Just look at the end of that Pittsburgh game and what he did last year [strip sack in the red zone to preserve the win]. He's like I was a few years ago in that he's in that prove-it phase. Hopefully, he and I end up being the best defensive end tandem in the league."

Earlier in the day, Griffen was asked how he thinks he'll respond to not only the big contract but the fact he's replacing one of the greatest defensive ends to play for the Vikings.

"I've got a workout at 10 o'clock [Wednesday morning]," he said. "I'm going to go right back to work. With more responsibility, that means you've got to work harder, you've got to be disciplined, and biggest thing is, you've got to listen."

Griffen then invited a reporter to his Wednesday morning workout.

"It's at Higher Power Training right here in Eden Prairie," he said. "If you want to come join me, but you might pass out in there, but you'll be all right. You can come and join me and you can see all of this hard work I've got for you."

The Vikings also re-signed backup guard-center Joe Berger to a one-year deal Tuesday. Whether they dip into the cornerback market with what should still be plenty of salary cap room remains to be seen.

"I don't care if they sign a cornerback, a safety, a linebacker or whoever," Robison said. "Just sign anyone who they think can help us win. It's time we start winning around here again."