Head Injury Litigation: Why No NCAA?

This is meant as a serious question. I was just reading a nola.com article about John Fourcade and his physical complaints that he attributes to playing football. After reading the article, I wondered how many times Fourcade was hit playing in the NFL and how many times he was hit playing in college. I suspect the latter number is greater.

I am curious as to why the NCAA and the colleges are not being sued in a class action. A procedural defense of the NFL to the lawsuit in Philadelphia is apparently preemption under collective bargaining agreements. The NCAA and colleges don't have that defense.

Has anyone heard any talk of the NCAA being sued?