GREEN BAY––The first day of training camp is in the books, and for the rookies on the Packers, they got to experience the unique atmosphere in Green Bay for the first time.

They took part in tradition of riding children's bicycles to practice that goes back decades in Packers history. And as for the work that got done on the field today, the first-year players got to know what it's like to play with urgency.

Things like minicamp and OTA are for learning. Sure the rookies want to make a good impression in the spring, but jobs aren't won and lost at that time of the year. At training camp, the stakes are much higher.

For first-round draft choice, Nick Perry, he's focusing on a change of position. After playing defensive end in college at USC, he's attempting to make the switch to outside linebacker at the professional level.

"I haven't come down with a set of goals yet," Perry told reporters following Thursday's practice. "I'm still trying to learn the position. Everything is still new to me, and just this whole position is new."

It's a transition that's going to take some time. He carried a 270-pound frame with him during the offseason, which he needed playing in the trenches when he played in three-point stance.

With the Packers, Perry is learning to stand up and do things like drop into coverage, something he did sparingly during his collegiate years.

"I think there's a lot more thinking now," said Perry. "Playing defensive end, it's just react, react, react. Now you have to think. You have to visualize everything that's going on around you. And I'm starting to do that more than usual. So it's been helping and we're working towards that."

As for fourth-round draft choice Mike Daniels, the first day of training camp provided the opportunity to hit the practice field for the first time since he was drafted out of Iowa.

Following the 2011 season, Daniels had surgery on his shoulder, which kept him from participating in the Packers' entire offseason program.

The rookie defensive lineman said he's working on his technique, trying to do the little things to improve his game.

"I just try to focus on the things I'm not good at, trying to perfect the things I'm not good at, and get even better at the things I am good at," said Daniels. "It's just overall being a football player, just trying to improve every day."

One advantage this year's rookie class has over last year's is that they actually had the benefit of an offseason program unlike in 2011 when the NFL locked out the players.

Even though everything is still relatively new to them, they at least have a knowledge base entering training camp. They've had their play books for months and at least had the benefit of receiving coaching back in the May and June timeframe.

As second-year player Randall Cobb explains, it's a world of difference from a year ago.

"It's actually a lot easier," said Cobb. "Year two, I know the offense, I understand how our offense is run, our gameplan going into every week."

It's difficult to pass any judgements about the rookies after one day of training camp. Under rules set for in the last collective bargaining agreement, teams aren't allowed to wear pads until after the first three practices.

For the next couple days the rookies will continue their indoctrination to the NFL, but by next week the boys will be separated from the men when the pads come on.