GREEN BAY, Wis. (AP) -- Even star quarterback Aaron Rodgers had has a learning curve at the start of training camp.
Rodgers is adjusting to a revamped group of receivers, which no longer has James Jones after the team moved on without Greg Jennings and Donald Driver last year.
Rodgers likes the depth and talent at the position, but is tempering his expectations for how things will shake out by the end of camp.
''I'm going to sit back and watch in the preseason as this unfolds,'' Rodgers said Friday. ''We have four preseason games for a reason, and there will be a lot of opportunities for those guys.''
Several players are competing for possibly just three or four spots behind top wideouts Jordy Nelson and Randall Cobb on the roster before the Packers kick off the season Sept. 4 at defending Super Bowl champion Seattle.
One of those young hopefuls is Jared Abbrederis. Green Bay selected the former Wisconsin standout in the fifth round of this year's draft, but the rookie suffered a knee injury that kept him out of practice Friday.
Coach Mike McCarthy didn't know after practice the extent of the injury for Abbrederis.
''I don't have a full medical report,'' McCarthy said.
Abbrederis attended practice and meetings Friday, but wasn't available during the open locker-room period for reporters.
Receivers coach Edgar Bennett said Abbrederis was making the most of his opportunities and off to a good start a week into training camp.
Rodgers is counting on similar improvement by the team's other young prospects at receiver as well as tight end. The Packers are looking to replace Jermichael Finley, who remains a free agent after suffering a career-threatening neck injury last season.
''It's a deep group, and they know that there's jobs up for grabs and there's a lot of opportunities to be had in that room and they're going to have some really good guys throwing them the football,'' Rodgers said.
The list of contenders to fall in behind the playmaking duo of Nelson and Cobb includes third-year player Jarrett Boykin; second-year players Kevin Dorsey, Chris Harper and Myles White; first-year players Gerrard Sheppard and Alex Gillett, the latter a converted quarterback; and rookies Davante Adams, Jeff Janis and Abbrederis.
The emergence of Boykin last season, when he finished third on the team with 49 catches for 681 yards and three touchdowns, might have impacted the team's decision to move on without James Jones after seven years. Jones signed with the Oakland Raiders in March.
Green Bay added big-play prospect Adams (second round), Abbrederis and Janis (seventh) in the draft, along with tight end Richard Rodgers (third).
Janis has yet to practice in the preseason because of an illness.
And the young guys may want to heed what Rodgers told reporters Friday on how they can gain his trust.
''It's really all about one thing - it's about mental preparation,'' Rodgers said. ''The physical mistakes are going to happen. There's going to be drops at times. There's going to be a not quite on the same page every single time. But if you cannot line up right, if you can't get the checks and if you can't do what you're supposed to do every time, then there's no way you can possibly be on the field when I'm out there.''
NOTES: S Morgan Burnett returned to practice Friday after being out a day. The returning starter suffered an ankle injury Wednesday. Rookie C Corey Linsley was sidelined Friday with a shoulder injury. ... The Packers will hold their annual Family Night event at soldout Lambeau Field on Saturday. In a change from previous years, the team will hold a practice instead of a scrimmage. Team president Mark Murphy said the festive event also would include a laser show for the first time and a fireworks display.
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