Adrian Peterson was isolated and upset. About four months removed from tearing anterior cruciate and medial collateral ligaments in his left knee, Peterson was upset — in April — that rookie tight end Kyle Rudolph and the rest of the receivers weren’t sprinting fast enough during half-gassers, a conditioning drill where players run from one sideline to the other and back.

“So, he came down from his rehab session and he ran with the team,” Rudolph recalled Thursday. “Adrian just, he kind of defied modern medicine with his recovery.”

Second-year running back Dalvin Cook finished Thursday’s joint practice with the Jacksonville Jaguars, the final day of Vikings training camp, with the same drill. In fact, toward the end of every practice that’s where you’ll find Cook and Latavius Murray, while younger teammates practice special teams and other veterans take a break.

His surgically repaired left knee free of any brace or support, Cook spent the dog days of camp impressing spectators with evasive, sharp cuts. But like Peterson in the lead-up to 2012, Cook has all but been encased in bubble wrap by a Vikings athletic training staff that knows a thing or two about returning a running back to full health. He didn’t play in last weekend’s preseason opener, or in front of fans during an up-tempo Aug. 4 night practice.

VideoVideo (01:58): Vikings running back Dalvin Cook says he trusts the coaching staff to play him when they're ready and has enjoyed having joint practices with Jacksonville.

Mike Zimmer, the play-through-it type of old-school coach, knows Cook’s value is too great. Zimmer has said he wants him to play at some point in the preseason, but won’t say when. It’s unlikely he will play much, if at all, on Saturday against the Jaguars because of both his potential and what he’s already shown in practices.

“When he’s out there, it’s easy to see,” Rudolph said. “I remember the first couple carries he had this offseason when he was just getting back into team periods, it was like, ‘Oh, wow, yeah that’s Dalvin. There he goes again making cuts no one else can make, finding holes no one else can find.’ ”

Cook wants the world to know he’s “ready to go” after last year’s season-ending injury in Week 4. Zimmer and Cook contend he could play in a game tomorrow. But the Vikings are focused on the Sept. 9 season opener against the 49ers, which still gives Cook more than three weeks to get into a game-ready condition. It’s been a crawl to get to the Sunday sprints.

“Each day we’re trying to stack on a few more plays, few more days in a row,” Zimmer said. “That’s really what we’re trying to do, is trying to get him in game-ready shape.”

The Vikings put more on Cook’s plate this week during back-to-back joint practices with the Jaguars. Previously, he’d rotate heavier and lighter workloads by day. On Wednesday and Thursday, Cook was featured prominently in 11-on-11 team sessions against the Jaguars’ No. 2 defense.

While he wasn’t tackled to the ground, those reps are the closest Cook has been to live game action.

“Your guys, they take care of you,” Cook said. “We take care of [the Jaguars], but it’s just a little different vibe to it that you got to have a little more pep in your step. You have to make those cuts more precise. It is different.”

The biggest hurdle for the Vikings is making all the new pieces mesh. Quarterback Kirk Cousins has yet to take a snap from his starting center, Pat Elflein, in a practice. He’s yet to hand off to Cook in a game. If it were up to Cousins, Cook would get at least some preseason reps before Sept. 9.

“I hope we can get a little bit of work,” Cousins said. “You do what you can. He’s coming off an injury, it is the preseason. We do have a lot of practice reps. We’ll get all we can get, realistically, and then go into Week 1 ready to go.”

The last hurdle for Cook will be getting into game shape. It’ll be more than 11 months since surgery before he suits up for another full game. Vikings rookie linebacker Devante Downs, recovering from his second torn ACL suffered at Cal, has already made the comeback once and knows the most challenging part of making a full recovery.

“Just getting back into football shape. A lot of things can prepare you like running sprints,” Downs said. “But nothing is like playing football.”