I'd say it is common. My son received a workout regimen from one of the assistant coaches in the summer before attending college. If you have not received one already, perhaps send them an e-mail asking for one.
Based on experience, the best advice you can give your son is to start training like Marine boot camp - yesterday. Run, run, and run some more until he is in superior physical condition. Challenge him to show up in the late summer/fall in the best shape of anyone on the team. If he starts a week before camp, it will be too late. Have him find someone who will push him now too his limits. Do as much speed training as humanly possible supported with strength training and good nutrition (fruits, vegetables, lean meats and cut out the junk food - especially sweets).
The quickest way for him to turn a coach's head and get on their radar is to show them he is in better shape than anyone there. They'll be challenging the team to grueling workouts (in the heat of summer) and if he can show them he is at the front of the line each time they are asked to run or perform some other drill, he'll get their attention.