For those of you who are younger, and never heard of this guy, he was a real life character. Here's his bio from the All-AFL website run by Ange Coniglio, who is a huge AFL fan in Buffalo. This will give you some insight as to why Headrick was a special player:
http://www.conigliofamily.com/Texans...ERRILLHEADRICK
An original Dallas Texan out of Texas Christian University, Sherrill Headrick was considered the Texans' and the early Chiefs' best linebacker, a hard-nosed, all-giving player. He left TCU after three seasons and played one season at offensive guard, center and linebacker in the Canadian Football League (1959) before joining the Texans for the initial AFL season, signing as a free agent.
His teammates called him "Psycho" for his rambunctious nature, a reputation he fueled by banging his head against his locker and working himself up to the point of nausea before games. The nickname also befit his style of play: in his first year with the Texans, Headrick set the standard for playing hurt, after fracturing a vertebrae in his neck in a collision in warm-ups before a game with the Houston Oilers. Despite feeling pain in his neck, he played the entire game. He learned of the fracture five days later, but went on to play the following week.
Hank Stram said that Headrick, who refused to wear hip pads, had the highest pain threshold he'd ever seen in an athlete. Headrick played with a broken neck, infected gums, and a fractured thumb. When an injury left the bone in his finger protrding from the skin, he popped the bones in place without missing a play.
Headrick had fourteen interceptions during his eight-year Texans/Chiefs career, returning three for touchdowns. He played in the franchise's 1962 and 1966 AFL title game wins and in the first AFL-NFL World Championship Game.
He was All-AFL in 1960, and an American Football League All-Star in 1961, 1962, 1965 and 1966. Headrick was selected by the Cincinnati Bengals in the 1968 AFL expansion draft and played for them one season.