GREEN BAY, Wis. -- Just about every receiver who stepped in front of the JUGS machine after practice on Wednesday had trouble with what Green Bay Packers receivers coach Luke Getsy wanted them to do.

With his back to the machine, Randall Cobb whirled around and before he could catch the ball, it drilled him in the, um, groin area.

As Cobb lay on the ground in agony (and perhaps embarrassment), Davante Adams caught the first one then dropped the next two before he finally secured a second catch.

In stepped Trevor Davis, the rookie who wowed just about everyone with his speed during the first two camp practices. It turns out, his hands are pretty steady, too. Davis spun around and caught the first one. He turned his back to the machine a second time and repeated the feat.

It’s only been two days of practice -- both without pads -- but the fifth-round pick from Cal is off to quite the start. On the first day, he made a one-handed sideline catch, and then twice outran defensive backs to haul in deep balls. On Wednesday, just minutes after coach Mike McCarthy said the next thing for Davis was to focus on the details of route running, he caught both a slant and a post during team periods.

As Davis beat rookie cornerback Josh Hawkins on the post, cornerbacks coach Joe Whitt could be heard saying "good route."

"You see the big plays, but it’s the details, the fundamentals, the little things, the discipline," McCarthy said before Wednesday's practice. "So you just want to see him build off of that, because he has shown that he can make big plays, but you want him to do the details that require the offensive player to be a first-, second-, and third-down player. He’s off to a good start."

The 6-foot-1, 188-pound Davis adds an element to the Packers’ receiving corps that was missing last season, when they were the slowest group in the league sans Jordy Nelson. Davis ran a 4.42 40-yard dash at the combine, and the Packers said they had him timed in the mid-4.3s.

"That’s what he’s here for," said Packers tight end Richard Rodgers, who also played at Cal and worked out with Davis this summer. "He’s fast, and you’ve got to run."

Davis doesn’t simply want to rely on his speed. He’s taken McCarthy’s comments to heart about learning the details of the position.

"All these guys I’m going up against and all the NFL people, they’ve all run the exact same time," Davis said. "It’s really the details that can set you aside, not the speed."

And, of course, his hands.

Rodgers has been praised for having the best hands on the team, but after watching Davis on the JUGS machine, he might have some competition.

"I don’t know about that," Rodgers said. "We’ve been having that debate for a while, because he was on the team at Cal with me. Obviously as people who catch the ball, we want to catch everything."