20. Tim Tebow
Sometimes momentum can hide the warning signs from the fans. Tebow starred in the Denver Broncos’ playoff run in 2011 but the coaches had their doubts about him. In the end, they decided to trade him to the New York Jets, where he went into a swift decline.
In short, that was the end of his career as a starting quarterback. He made 12 appearances for the Eagles but only two from the start as opposition teams exposed his game. From there he trained with the New England Patriots and the Philadelphia Eagles, but neither of them wanted him.