If Griffin wants proof that individual play can improve less than a year after a torn ACL, he need only watch Peterson when the teams meet Thursday night.
Because they don't play the same position, it's not a direct comparison. Griffin's passing -- and evolution in the passing game -- was hurt by his lack of an offseason, so even having a knee that feels good won't always help.
Peterson just needed to feel stronger and confident.
"Coming off an injury it's never easy, but you always believe you can go out and just be fine right away," Griffin said. "I think Adrian felt the same way. ... The latter part of his year last year was an amazing run, and people don't even worry about the beginning of the season based on how it ended, and it ended with an MVP for him. I'm not focused on those things. We've got to get another win."
Griffin says he's not focused on individual awards, but he does understand the roller-coaster performances after a torn ACL. Another difference is that Peterson had never torn his before; Griffin first tore his in college. Also, Griffin needed to have his posterior cruciate and medial collateral ligaments repaired. Peterson, who had his surgery in late December 2011, did not. Still, both were determined to return for the openers the following season and did so.
Peterson said Griffin spoke with his personal trainer.
"He was able to give information on stuff I did during my recovery and some things that would kind of help him out," Peterson said.
In 2012, Peterson had a good first half with an NFL-best 775 yards, averaging 5.13 yards per carry. It's only 64 more yards than he's gained this season. Then Peterson exploded, finishing with six games of at least 150 yards -- and five with more than 170 -- en route to 2,097 yards.
"I never really felt like I was 100 percent as far as the power in my left leg," Peterson said. "But I want to say around about Week 5 I really felt strong and confident in my leg -- the strength of my leg -- but I still knew I had a little ways to go."
Griffin has had an uneven first half of the season, and his legs have been bigger factors with each passing week -- although that often depends on how defenses play him, just as it mattered a year ago. Griffin has finished five games with a passer rating of less than 90. His throws have been off-target more often than last season, in part because of different coverage schemes. In his first half last season, Griffin posted five games of 90-or-higher ratings.
But he's also run the ball more effectively of late and is coming off his best passing game of the season: 23-of-32 for 291 yards against San Diego. Last season, he clinched a win over the Vikings with a 76-yard touchdown run late in the fourth quarter.
"You can see he's really looking more and more like the Robert from a season ago," Vikings coach Leslie Frazier said. "So he's coming into his own. You can definitely see the difference."
Peterson has watched, knowing the path Griffin has needed to take.
"I can definitely tell he's more comfortable than he was at the beginning of the season," Peterson said. "He's improving each week."
And Griffin can look forward to 2014 knowing the strengthening will continue.
"I'm more confident and stronger than I was last year," Peterson said. "So I was ready to roll."