GREEN BAY, Wis. -- Sam Shields had a pretty good idea what Ty Montgomery could do after watching him the first three days of training camp. That didn't help Shields, the veteran Green Bay Packers veteran cornerback, one iota when he came face to face with the rookie receiver midway through Monday's practice.

The 6-foot, 216-pound Montgomery had just snagged a short pass from Scott Tolzien in the left flat and turned up the field. As Shields lined up for the tackle, Montgomery's hips shook, freezing the speedy cornerback in his tracks.

A second later, Montgomery crossed the goal line. Untouched.

"When he first got here, you could tell how quick he was," Shields said. "That move he did, I played the right leverage."

And then Shields smiled and shook his head, almost as if he were still in disbelief.

"But it was quick," he said.

So far, the third-round pick has shown off his physical skills -- "strong, very powerful, obviously gifted," Packers coach Mike McCarthy said on Montgomery after the first full-pads practice on Saturday. But what only those behind the scenes at Lambeau Field have seen is how the 22-year-old from Stanford has prepared for moments like Monday.

"Taking away the athletic part of it, just his approach to understanding our playbook, asking questions, trying to be detailed as much as possible in a short amount of time," Packers receiver Jordy Nelson said. "He's not just worried about having a 15-yard puma [route] but knowing what he has to do within that.

"We give him a hard time that it must be the Stanford coming out of him, but I think it's the detail and the effort that he's putting in to understand that he's going to be part of this and that he needs to get going. Sometimes you see that more with some guys than with other guys, so it's great to see that. As an older guy you have appreciation for that because then you want to help him out and you understand that he's going to retain it and you see the impact."

So far none of the questions about his hands -- he had a few games in college with multiple drops -- have even been worth bringing up. He hasn't dropped a ball during a team or group drill so far in camp.

And then there's his versatility. Already in the first four days of camp, Montgomery has returned kickoffs, lined up at receiver, caught a shovel pass out of the backfield and run the ball on an end around. Montgomery scored three touchdowns in team drills on Monday -- the juke move against Shields, a post from Tolzien and a shovel pass from Matt Blanchard on a goal-line play. Shields went so far as to compare him to Percy Harvin.

If the rookie indoctrination process seems like it's going fast, that's news to Montgomery.

"To be honest, I've never seen anyone go through it before besides the guys that are here with me," Montgomery said. "So I can't tell you if I think I'm accelerating the process or how to do it, I just know that I'm just me. I ask a lot of questions. I've always been that way because I just want to make sure I understand everything and I want to understand why everything is the way it is. I think that makes anything easier when you start to understand why because you don't have to just memorize it."

Much of Montgomery's work so far has come with the second stringers. Snaps with the starters are tough to come by with Jordy Nelson, Randall Cobb and Davante Adams -- the top-three receivers from last season -- all back and fully practicing with Aaron Rodgers.

But Rodgers, too, has noticed Montgomery.

Just don't give any of that Stanford business to Rodgers, who went to rival California.

"He's not maybe Cal smart -- I'm going to take shots at his school as much as I can -- but we're excited to have him," Rodgers said. "He's going to be a good player for us, we think, and the best thing is he's got a great attitude and a great approach."

Oh and those physical skills aren't bad, either.

"No, but everyone sees that," Nelson said. "Some people have that athleticism, but if you don't understand it and can't get it and don't have the trust of the quarterback, it doesn’t matter what you can do otherwise."