re: Random athletes that you thought would have long careers but never did

I'm obviously projecting at this point but RG3. He was the #2 pick and had a great rookie year and led the Redskins to a division title. Shanahan broke him and he lost the starting job and now he's on to Cleveland, which is never a good thing for a QB. It's still possible for him to have a long career, but it almost certainly won't follow the trajectory I thought it would