They very actively recruit. The SAs bring in very large recruiting classes for football each year. Usually around 30-40 direct admits and 30-40 from NAPS. Obviously 60-80 recruits do not make the squad. Most leave by natural attrition, they realize they simply aren't good enough or they don't want to put the time in. Since there are no scholarships, you stay at the the SA with no issue. Out of all those who start out as a football recruit, senior day usually has 15-30 seniors each year. Of those who get celebrated that day, usually half received any quality playing time. I mention these numbers because recruiting at a SA is unique. Not many make it 4 years as an athlete and its a huge time commitment.