Tough as nails, as Alex Hawkins, a teammate, vividly shows in this excerpt from his book My Story
The Bears were in front 20-17, and the Colts had the ball inside the 40-yard line, with just seconds remaining in the game. On third down, Unitas called a deep pattern to Lenny Moore. He told me to stay in and block. The Bears were blitzing, and Bill George managed to get hold of one of John's legs. George held him long enough for Doug Atkins to get free and finish him off....
John was slow getting up; we knew he was hurt. The trainers and doctors were running onto the field as Doug stood towering over John's limp body. Doug just stared down at him for a second, and then he spoke: "Well, kid, that's about it for you today."
John propped himself up on one hand and replied, "Not just yet it ain't." When I saw John's face, I almost threw up. His nose was slashed and mangled, and his face was covered with blood. It was as if he had been hit with an ax.
Have you ever noticed how deathly quiet things get when a great player goes down? A hush settled over Wrigley Field as they took John to the sideline.... After packing his nose full of cotton, he trotted back on the field. When he reached the huddle, his nose had already swollen to twice its normal size, and both eyes were almost swollen shut. On fourth down, with no timeouts and only 19 seconds left on the clock, John called the identical deep pattern to Moore. Lenny beat his defender as Unitas uncorked a perfect 39-yard scoring strike to win it 24-20.
It was the most dramatic finish and the damnedest spectacle I had ever seen. Things like this don't just happen; they're caused. The man who caused this one, John Unitas, just walked off the field as if it were an everyday occurrence. No high fives, no dancing or celebrating, no fingers pointed upward designating "We're Number I." Here was the greatest quarterback who ever played the game, walking casually off the field, having just finished a day of work. This was what he was paid to do. How often do you see that kind of dignity anywhere?