MANKATO -- The Vikings decided to do some heavy hitting in today's practice. Wisely, they decided to make a certain reigning league MVP a spectator for the real rough stuff.

"I really didn't get involved with the full contact," running back Adrian Peterson said. "But it was good sitting back there and watching things develop."

Peterson spoke to reporters for about eight minutes after practice. Here are some of the highlights:

On the overall tone of the practice, which clearly was won by the defense: Defensive tackle Letroy Guion looked like Mean Joe Greene on a couple of penetrating goal-line stops. And backup strong-side tackle Larry Dean had the hit of the day when he sliced through the line of scrimmage and lit up running back Toby Gerhart. Dean was running with the first team as Chad Greenway was getting some rest.

"The defense kind of handed it to us today, to be honest," Peterson said. "But I seen some good things that we're doing offensively with the quarterbacks, receivers and offensive line as well."

On his initial reaction to the new NFL rule that players can't lead with the crown of their helmet:

"I didn't like it, to be honest, initially because I kind of misunderstood the rule. I thought it was just pointing out the running backs, and I thought that was wrong, all the way wrong. But in the big picture of things, you hear a lot about guys injuring themselves with their head down. So for the sport and the health of the players, it's a good rule. When I found out that it includes all players, I was cool with it."

On whehter it will affect him:

"Not really. But I'm sure sometimes it's natural instincts to have my head down. Hopefully, they miss it."

On what he thought of the NFL using Peterson as an example in their video about the new rule:

"It's cool. I didn't mind at all."

On where he sets the bar for himself this season:

"I've said 2,500 [yards]. I'm not trying to make a big deal about it because I'm being asked about it all the time. But I'm always finding ways to challenge myself. People are trying to shoot me down because they don't want to challenge themselves in any way. This is the way I've been successful, challenging myself and setting goals and high expectations. So win a Super Bowl first and foremost, obviously. But 2,500 would be nice."