Packers quarterback Aaron Rodgers sat on the bench behind Brett Favre for three years before he took over and became the highest-rated passer in NFL history.
He believes that apprenticeship benefited him as it can Chicago Bears rookie quarterback Mitch Trubisky.
"A lot of it's mental," Rodgers said. "Obviously getting picked in the first round, the physical aspects were there with Mitch. (He) had a good preseason, made a lot of plays, ran around, did some good things from what I saw.
"But mentally it takes awhile to learn the offense and, more importantly, start to learn defenses and put together fronts with pressures and coverages and start to see some different things on film.
"The game is a little different preseason to regular season. A lot of different levels of preparation go into it."
Despite not playing, Rodgers said he found ways to improve, like throwing to practice squad players and running the scout team during the week.
Trubisky has mentioned the same things when asked about his ability to grow without actually playing in games.
"I valued all of it at the time," Rodgers said. "In 2005, I don't think the quarterbacks were as ready to play as maybe some of the guys are now. And so, for me, it was just about learning, taking some more time, getting my body in great shape.
"I was very thankful for the opportunity to grow, but I was never bitter in the moment. I was always excited about every day of practice and excited about going through my preparation during the week to trying to give maybe one little nugget to Brett during the week that might help him play better on Sunday."
Letting it go:
Cornerback Marcus Cooper cost the Bears a touchdown when he had the ball knocked out of his grasp from behind just a yard short of the end zone. He inexplicably slowed down near the goal line on what should have been a 71-yard TD return of a blocked field goal.
It was infuriating, but coach John Fox was diplomatic when asked about the egregious mental mistake.
"In this league … you have to have a short memory," Fox said. "Look out the front window and not the rearview mirror. Don't look too long in the rearview mirror or you'll wreck.
"You kind of learn from those things and move on. He's a professional, and he moved on. I mean, we're not firing him. He's too much a part of our team."
Safety Adrian Amos started all 16 games as a rookie in 2015 after being drafted in the fifth round (142nd overall) out of Penn State and 14 more last year.
Amos lost his job to rookie Eddie Jackson, but now he's back in the starting lineup because of the fractured forearm that felled Quintin Demps.
Defensive coordinator Vic Fangio said, "We'll find out," when asked how the Jackson-Amos duo would work out, and his message to Amos was simple.
"All you say to him is, 'Let's go,' " Fangio said. " 'Here's your second opportunity. You knew it would come again. It's come early. Let's go play good.' "
Guard Josh Sitton (ribs) and center Hroniss Grasu, who were limited this week in practice, are both questionable for Thursday night.
Safety Quintin Demps (fractured forearm) is out and linebacker Nick Kwiatkoski (chest) is doubtful after not practicing all week.
For the Packers, both starting offensive tackles, David Bakhtiari (hamstring) and Bryan Bulaga (ankle), are doubtful. Three backups tackles are on injured reserve: Jason Spriggs, Kyle Murphy and Don Barclay.
Defensive tackle Mike Daniels (hip) and linebacker Nick Perry (hand) are questionable. Cornerback Davon House (quadriceps) is out.
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