Best to push a kid into sport at 3-4 years old. A bit hard now.

My best guess is to try baseball. It is not as aggressive as soccer, lots time to bench with other kids.

The other thing is being tough to him. When he cries, just tell him "suck it up! You are a boy, you should be playing sports, not crying!" All kids have this difficult time, parents have to be persistant and tough as well.