He can absolutely finish his degree while playing professionally. But if he goes pro after two years in college, it's very unlikely. In practice, he can continue taking classes online/by correspondence/during the offseason, but Student athletes get to enroll in special course sections that have fewer hours and expect less work, and once he moves on to the pros he has to take real courses.
I suppose it might be a lot easier now with online classes, but nonetheless, probably something to do after playing career is over.