Cooper Manning was once able to make tough guy Peyton Manning cry on the football field -- but that was back when Peyton was toddler.
In this home-movie footage, the future Super Bowl Champion cries and howls at older brother Cooper, saying "That hurts!" and "You can't grab my neck!"
The clip comes ahead of Tuesday night's ESPN documentary "The Book of Manning."
Cooper says youngest brother Eli -- two-time Super Bowl champion as quarterback for the New York Giants -- was nothing like Peyton as a kid.
"He wouldn't cry," Cooper said of Eli.
Cooper, a one-time high school receiver whose football career ended with a diagnosis of spinal stenosis, is a primary figure in "The Book of Manning," which tells the stories of the sons of legendary New Orleans Saints quarterback Archie Manning.