– The shock of being out of the year already has worn off for Jordy Nelson.

One of the first things to cross Nelson's mind upon returning to Lambeau Field on Tuesday was to get into the classroom to help get the younger receivers up to speed at training camp.

There's a huge void to fill in the Packers' potent offense with Nelson sidelined for the season after tearing the ACL in his right knee Sunday during a preseason game in Pittsburgh.

"They're going to be running the same plays we've always ran so [there are] little tidbits I can give them. I hope that it wouldn't be any different from than when I was playing," Nelson said. "I'd still be trying to coach them up as much."

It would be so much easier for the Packers if MVP quarterback Aaron Rodgers' top receiving target was around to torment secondaries again. Nelson led the highest-scoring team in the league with 98 catches for 1,519 yards and 13 touchdowns a year ago.

Nelson was hurt after jumping to catch a short pass from Rodgers at Heinz Field. He landed first on his left foot before coming down on the right foot and turning to go upfield. He didn't get hit.

There wasn't much pain, Nelson said.

"That's why I just ran off the field, didn't think it was anything serious and obviously I was told different," he said.

By halftime, Nelson said he had an idea his season might be done, even though coach Mike McCarthy held out hope that more tests in Green Bay might yield a more optimistic diagnosis.

For now, the focus shifts to young receivers who will need to step up behind Randall Cobb and promising second-year receiver Davante Adams. Second-year players Myles White and Jeff Janis have limited experience, and rookie Ty Montgomery has had a promising training camp.

"Guys have just got to step up. Plain and simple. Nothing else to be said. It just has to be done," said Montgomery. Until Nelson's injury, Montgomery seemed to have a hold on the No. 4 receiver slot.

This will be a critical week for those younger receivers to develop the rapport and earn the trust that Rodgers had with Nelson, who was going into his eighth year in the league. The Packers play their first preseason home game of the season Saturday.