You would ejaculate less sperm cells. That is not too bad since you can still reproduce. In some cases, you might need some testosterone supplementation.
Having one testicle is not going to have any affect on your ability to play football.
It should not affect performance however may effect sperm count and reproductive capability.
A guy with one testicle will have the same change in his voice that he would have if he had two.
Is having just one testicle normal, no. Normal is men have two testicles, but it does happen. Sometimes due to an accident or illness, sometimes a boy is born with only one developed testicle and as long as it is healthy, your sex life and fertility will not be effected. Make sure you see a doctor to ensure you don't have an undescended testicle or a hernia. If the second testicle is trapped in your abdomen, it can be strangled and the one testicle you can see could end up slipping through the hernia too.
A 30 year old will have no problem having children if he has only one testicle, as long as that single testicle is in good health.
Not if only one testicle is removed. You can produce sperm just fine with only one testicle
increase stamina
It is normal for one testicle to be slightly smaller than the other. The difference in size does not affect fertility.
Yes, as long as the testicle is functioning properly then you can reproduce with one testicle.
Yes, he has only one testicle.
yes you can (I did)
Can a man with one testicle breed? The answer is YES