The Cleveland Browns set themselves back for almost a decade because they selected Manziel. He had a successful career with Texas A&M but the NFL is a different level. Many scouts doubted his temperament and questioned if he had the right mindset to be a starting quarterback. His partying was the stuff of infamy but he didn’t change when he got to the pro ranks.
Manziel’s immaturity damaged his standing in the sport. Meanwhile, he used drugs as if the world were ending. There was also a messy domestic violence incident with his girlfriend that brought him into disrepute. In the end, the quarterback fell out of the NFL after two seasons before failing to make the grade in Canada (via Sportskeeda).