It took most of the offseason, but Greg Jennings and his agent got what they wanted from the  Green Bay Packers.

The three-year contract extension the rising receiver signed on Wednesday financially sets up him and his family for life — and also gives Jennings the chance for another big-time payday before he turns 30.

“That’s the beauty of it,” Jennings said shortly after the Packers announced the deal, which contains roughly $16 million in guarantees.

“Kudos to my agent — Eugene Parker is one of the top agents at doing what he does best, and that’s negotiating contracts. That was pretty much our game plan, if there is to be a career after this contract. Again, I can’t tell the future, but that was definitely the game plan, to make it a situation where I would have another opportunity to go to the table and redo a deal.”

Added onto the remaining year of his rookie deal, the extension — which could pay Jennings in the neighborhood of $30 million if he earns all incentives — runs through the 2012 season.

Jennings, 25, will be 29 when his new deal expires. So, he’ll be young enough at a position with a relatively short shelf life that a team probably wouldn’t hesitate to invest top dollar if his career continues its upward trajectory.

It’s also possible the Packers will be in the same position again three years from now, willing to extend their top offensive threat with a year to go on his contract.

All that depends on Jennings’ performance, which has improved markedly in each of his three NFL Football Seasons.After battling injuries while catching 45 passes for 632 yards and three touchdowns as a rookie, Jennings broke out in 2007 (53 catches, 920 yards, 12 touchdowns) and then surpassed veteran Donald Driver as the Packers’ No. 1 receiver last season, when he played in all 16 games for the first time and finished with 80 catches for 1,292 yards and nine scores.

“We’re excited for Greg Jennings’ future here — there is no doubt,” Packers coach Mike McCarthy said. “I think Greg is a young man that has developed here in Green Bay, and I can’t say enough about him personally. I like the way he goes about his business, and he is definitely well-deserving of this contract.”

A former second-round draft pick (52nd overall) in 2006 who was due to make only $535,000 this season under his old deal, Jennings acknowledged there was “definitely a sense of urgency” to do a deal because of the NFL ’s uncertain labor situation. If a new collective bargaining agreement isn’t in place by the start of the 2010 league year, the salary cap would disappear and players with fewer than six accrued seasons — Jennings would have only four — would become ineligible for unrestricted free agency.

Rather than take a chance, the married father of two agreed to terms on a deal that makes him the Packers’ second-highest-paid player, behind only quarterback Aaron Rodgers. Jennings also becomes one of the NFL’s highest-paid receivers by any measure, despite having yet to make a Pro Bowl.