Most men's testicles are about the same size, but it's common for one to be slightly bigger than the other. One testicle may also hang lower than the other one.
I wish him the very best in his recovery. A terrific manager for us and someone who people just seem to respect. I've never heard a bad word said about him from Oxford fans and that says it all when you consider he's now managing a rival team in the same division. Get well soon !