Question for Sports Law guy

There's been some talk on this board about the UT guys who were arrested a few days ago when drugs were found in the car they were riding in. Now there's a story in today's Morning News that says their lawyer has a letter from another student who admits to owning the drugs, etc.
Without getting in to the specifics of the UT case, when a student-athlete is arrested and retains a lawyer (and assuming they don't have lots of disposable cash to pay for a lawyer) - do they have to pay for the lawyer themselves? Is it legal for some rich booster to pay the lawyer? Do they have to find a lawyer (perhaps a school donor, season ticket holder, etc.) who will take the case for free?
Again, I'm not asking specifically about the guys at Texas. But there are always stories about athletes getting into trouble, and I was curious.
Without getting in to the specifics of the UT case, when a student-athlete is arrested and retains a lawyer (and assuming they don't have lots of disposable cash to pay for a lawyer) - do they have to pay for the lawyer themselves? Is it legal for some rich booster to pay the lawyer? Do they have to find a lawyer (perhaps a school donor, season ticket holder, etc.) who will take the case for free?
Again, I'm not asking specifically about the guys at Texas. But there are always stories about athletes getting into trouble, and I was curious.