Mike McCarthy has taken over as coach of a storied NFL team that just might be headed for hard times. ? Two of the Green Bay Packers? best players, halfback Ahman Green and receiver Javon Walker, are coming off serious injuries with no guarantees they?ll be what they were. ? Quarterback Brett Favre might retire. ? The team is coming off a 4-12 season, its worst since 1991, the year before Favre arrived. But McCarthy, 42, who was named the Packers? coach on Jan. 12, insists his team is not rebuilding. With the unbounded optimism that goes with a coaching change and having almost finished hiring a coaching staff, he has his sights on getting the Packers back to the postseason in 2006. ?I wouldn?t say it?s a rebuilding project, because those are ifs, they?re not exacts,? McCarthy said of Green, Walker and Favre.