The best players are easy to spot during their college years and are usually the top players on the roster at a position. Quarterbacks are the easiest type of talented player to identify.

But the difference between college football and pro football is big, so big that it's overwhelming for some college players who come to the NFL with hopes of playing the same way they did in college.

Another problem that destroys young football stars is money, contracts and money corrupt the minds of these players and at the end of their first rookie season they don't achieve anything important.

8 Promising college football players that failed in the NFL

1. Jhonny Manziel: He will be remembered as one of the biggest NFL busts of the last 20 years, but in college he was a star like no other.

2. Colt Brenan: His time with the Hawaii Rainbow Warriors was perfect, but when he was drafted by the Washington Commanders things changed, in his rookie season Brenan got injured and the Commanders relased him.

3. Vince Young: Who would have thought that after an incredible college career he would only play with the Titans and Eagles in what was a short 6-year career in the NFL where he won Offensive rookie of the year.

4. Jacke Locker: At one time Locker was the hope for the Tennessee Titans but his inconsistency was not something expected in the NFL, during his college career he threw 53 touchdowns.

5. Denard Robinson: Just three years in the NFL was enough for his pro career to end, his best plays were with his college team but he never played the same after he was drafted.

6. Marcus Lattimore: Injuries were what ended what would have been an incredible NFL career for him after being considered a top running back, but life had other things in store for him.

7. Noel Devine: Tagged as the best running back available no NFL team drafted him instead he had to settle for playing in Canada during his 'pro football career'.

8. Andy Katzenmoyer: Another young player who couldn't shine in the NFL due to injury, but at least he was a Super Bowl champion with the New England Patriots.