GREEN BAY — Carl Bradford likes to play a certain way. The 21-year-old rookie fourth-round draft pick thinks the pepper he puts in his punch makes him a physical, attacking nuisance to the guy he’s facing on offense and he is sure it will distinguish him on the Packers’ crowded practice football field.

But he has yet to put a decent lick on anyone in the Packers’ organized team activities.

“I believe we would get yelled at,” said Bradford, a linebacker out of Arizona State. “That’s why I haven’t done it yet.”

There’s a reason why you’re not getting a lot of quality evaluation of the Green Bay Packers at the moment. There are non-contact rules that everyone must abide by as part of the collective bargaining agreement and they’re pretty serious.

When Dallas linebacker Sean Lee tore his ACL last week, the NFL Players Association investigated by watching the Cowboys practice film to see whether the team was going too fast or too aggressive. Lee did collide with a teammate, rookie Zack Martin, but ultimately the union decided the injury wasn’t a direct result of the contact.

But Lee’s injury should put the Packers and the rest of the NFL on notice to know exactly what the non-contact rules are, because they could otherwise be penalized with fines and lost practice days.

“First week, second week, everybody is excited,” said fourth-year linebacker Jamari Lattimore. “But then you’ve got guys that don’t know how to practice with the other guys who have been here. It’s a learning process all over. Every year is new.

“And it is hard, because they’re telling us to go full speed, and it’s the nature of the game to go full speed. But when you’re going full speed and it’s time to make impact, you’ve got to back off. It takes time to learn how to go, and stop, go, and stop.”

The non-contact OTAs may irk NFL coaches — read between the lines and Mike McCarthy doesn’t always seem amused by the rules — but the NFL off-season is now largely for show. There are no one-on-one offense vs. defense individual drills allowed. There is no live contact anywhere. No one can wear pads.

“One of the reasons they did that was so we can have career longevity, so as players, we have to respect that,” said receiver Randall Cobb.

What’s the point, then, of off-season practices? There are several. Even though they’re voluntary, everyone is expected to attend and to keep their understanding of the playbook sharp. It’s also a way for the staff to check on the physical condition of the players. Everything else on the grass is a demonstration of form and technique.

And that’s fine for the established veterans who have nothing to prove and little to gain by playing as hard now as they would in training camp.

But everyone else wants to make a good impression. Drafted players want to prove they were worth it. Undrafted players want to make it. Injured players want to test themselves and kickstart their comeback.

“You can get better in the spring — but we’re not winning any games right now,” said fullback John Kuhn. “It’s all about technique and getting the play down and understanding the schemes more than anything.

“Later we can put the pads on, but right now you should really be looking out for your teammates and make sure everybody makes it to training camp.”

The self-policing of the non-contact rules have to come from everybody, too. It can’t just be from the coaches or just the players.

“If it comes from the players who say, tone it down, then the coaches will say … tone it up!” said Lattimore.

There are very subtle signs of the Packers backing off in these OTAs. Defensive backs race upfield to close in on receivers but as soon as they’re in range, they pull up. When a teammate is caught in a vulnerable position — with an ankle caught in a tangle, for example — someone will pull him up instead of tackling him to the ground.

“You practice good techniques, so that when you approach, you don’t have to tackle through the guy,” said rookie undrafted free agent linebacker Joe Thomas.

“You still want to get your hands on him — you don’t want to be too soft — just let him know you’re there,” said Bradford. “I think a lot of the guys understand that we have key players on this team that we can’t go too hard on them.”

That’s also an important thing to keep in mind. This time of year, the offense always looks way ahead of the defense, but part of that is because players on offense don’t play with any handcuffs.

“As a receiver, I’m not dialing back. It’s like a track meet every day for us,” said Cobb.

Do the players like the rules? That depends on whom you ask.

“I follow the rules and do what I’m supposed to do,” said Lattimore. “I don’t want to say anything I’m not supposed to say.”

“The younger me probably wouldn’t answer like this, but I try to come to work and do what they tell me to do,” said defensive lineman Letroy Guion. “And try not to get hurt. I try to play with my technique and take the right steps.

“As you grow up a little bit, you kind of get an understanding between the offense and the defense.”

So players are a little more careful around the line, where a lot of legs can get tangled up, and they’re watchful out on the islands, when receivers and defensive backs are leaping for the same catch. That’s something the youngest NFL pros have to understand.

“When I was young, I would have thought you go out and you dive for balls and you get on the ground and you wrestle around,” said Kuhn. “It’s just something you learn, and you hope that your veterans have enough vocal power to relay that to the young guys, and the young guys have enough respect to follow that model on the field.

“You tell guys to tone it down, you’re going to hurt either one of us or yourself. I think guys get the picture really fast to realize what the pace is right now during OTAs and minicamp. When training camp comes back, everybody flips the switch and doesn’t hold back.”