William Paul Daniel (November 10, 1937 – June 29, 2015) was an American football defensive back who played nine seasons in the NFL.

[2] He went undrafted in the 1961 NFL draft but was signed by the Pittsburgh Steelers, where he played for six seasons and made 11 interceptions and one touchdown.

Within the last decade of his life, Daniel suffered from dementia attributed to the numerous concussions he received during his football career.

He donated a portion of his brain and spinal cord for the project in hopes of developing procedures and equipment to make the sport safer for athletes.

[4] He was one of at least 345 NFL players to be diagnosed after death with this disease, which is caused by repeated hits to the head.