Alexander Mattison says failure helped him improve in first year with Vikings

Running back Dalvin Cook, who hadn't done much work in team drills during the Vikings' first three practices of training camp, saw more time in 11-on-11 drills Tuesday, getting several carries out of the backfield and catching a swing pass.

The Vikings' decision to limit Cook's early workload, though, has meant more first-team work for Alexander Mattison, the 2019 third-round pick who ran for 462 yards in a complementary role last year.

Mattison (above) proved himself to be a better open-field runner than many expected he'd be coming out of Boise State, with four of his 100 carries gaining at least 20 yards and another 11 going for at least 10.

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His ability to leap over defenders — a product of his time as a hurdler in high school track and field — landed him in a Super Bowl commercial, providing a thrill to his family when they saw the highlight show up on their TV in February.

The source of progress during his rookie year?

"I would probably say failure," Mattison said in a videoconference Tuesday. "Going out there and you fail a couple times, you learn from your mistakes, you hit the film room and you go out there and get back to it.

Mattison gives the Vikings insurance — and his name could be mentioned in their search for leverage — during the team's negotiations on a contract extension for Cook.

For his part on Tuesday, the Vikings' No. 2 running back said he hopes for the best for their No. 1 back.

"I don't know too much about [Cook's negotiations]," Mattison said. "I just know that he's a leader. He comes in here every day ready to work. So yeah, wishing the best for him. He's a leader in all sense of the word in the running back room and out there on that field."

Jefferson impresses again

The Vikings' Tuesday practice was the final session of camp that the team planned to livestream. It was more lively than the one fans saw on Monday, as the team tested its young cornerbacks with a busy day of downfield shots.

• First-round pick Justin Jefferson worked with all of the Vikings' offensive units as the team tries to get the receiver more practice time before the season. He had an impressive connection with Kirk Cousins on a deep throw off play action, and made plays with the Vikings' second- and third-team offenses as well.

• During his work with the first-team defense, rookie cornerback Cameron Dantzler intercepted Cousins on a play-action throw for Bisi Johnson. It was an up-and-down day overall for Dantzler, who got beat in coverage at least once, but the Vikings continue to give him chances to prove himself against veterans.

• Danielle Hunter sat out again with what coach Mike Zimmer described as a "tweak" on Monday; the defensive end made an appearance on the sideline later in practice.

• Dan Bailey continued his perfect start on field goals, making four on Tuesday to improve to 7-for-7 so far in camp.

• The Vikings continued to rotate Aviante Collins and Dakota Dozier at left guard, alongside the four players who seem established in their offensive line spots: Riley Reiff at left tackle, Garrett Bradbury at center, Pat Elflein at right guard and Brian O'Neill at right tackle.