Tough to do. Their seasons are at same time. To walk on he'd have to give up soccer scholie, or ...

he would count against the football team's 85 man limit. So the coaches need to be sure he would be worth it,

What he could do in the beginning is try kicking during spring drills and spring scrimmage, since the limit doesn't apply to spring practice. Let himself and the coaches see how he does at that level. If he wins the job in the spring, then he would have to decide. I would think he would have to give up soccer unless the football and soccer coaches would be willing to share his time. If the two teams practice at different times, it is conceivable, but really tough. While the football coaches might be more flexible with a kicker, the soccer coach needs him at practice. So, the demand on his time would take a lot away from his studies and student life.

Like I stated, it would be really tough to do.