"When Donovan McNabb entered the NFL in 1999, it was rare for quarterbacks to start as rookies.

"There wasn't a calling to try to get young guys in as fast as there is now," the Vikings quarterback said. "There was a process where you had to learn certain things, be able to see certain things on the field and the team had to have confidence in you. Now, some teams need to have their guy go in right now, for financial reasons or whatever."

Lions quarterback Matthew Stafford might have had the best of both worlds. He won the starting job as a rookie, but only played in 13 games his first two seasons because of injuries.

"Ever since I have played football I never sat out a year," Stafford said. "So I never knew what that was like. I just wanted to play and learn from that.

"Every team is different and every situation is different, but I didn't play all 32 games those two years so I had some time to sit and watch. I had about as good a mix on that as anybody.""