If they are really that bad, and you aren't planning on going to a DI job soon, since this would kill your reputation; sign them for $110, which would be a start and a scholarship. Than dont start them and get the recruiting money back next season.
Not sure what you meant by fill upperclassman spots. If you're balancxing your classes and specifically want juniors then you can still sign them for $110, youd just have to start them to keep them.