As the leader of the secret organization the "Vigils" Archie and Obie are scouting out potential new recruits. Archie notices that despite Jerry's physical stature, and his repeated poundings at practice, he still keeps getting up. Jerry is nauseous (7) his breath is constantly driven out of him (8) but he is determined to try out for the most vital position on the team--the QB. Archie notices Jerry's tenacity and his heart, and that his getting up is evidence that Jerry is an independent and determined young man. Archie sees Jerry as "a tough one" and as "stubborn" (16).
On another note...football is just a game, but how we play is sometimes how we approach life.