I had a young cockerel once that injured his leg - I assume jumping off something. It was just after he began to start breeding.
Now I have to say that it was hilarious watching this injured fellow try to mate. The girls learned how to side step when they didn't want his advances
But back to the story...
He was perfectly healthy otherwise. I tried to give him extras like the liver, etc., but he'd feed it all to the girls. Even when I separated him he'd feed them through the wire.
I tried separating him a bit so he could rest it. Nope. Wouldn't have it. He literally made his comb bloody by pacing up and down along the hardware cloth and it was rubbing on the wire. So I just let him out.
He learned to run by hopping on one leg - and was fast. He'd go everywhere they went - still hopping on one leg and still being the "protector".
On occasion I'd see him put a little weight on the leg, but mostly hopped everywhere.
Then about 3 months later, he began to use the leg more and more untill, by the time he was about a year old,
you wouldn't have been able to tell he had an injury at all. Even after having hopped for at least 3 months and probably more like 4-5.
When he first started favoring the leg, we looked him over very well - trying to find a break or any obvious injury but could find nothing. Since he was bright eyed and not showing any signs of illness, we just let him go to see what would happen.
I did keep trying to give him extra nutrition that should have been helpful for healing that kind of injury but I'm not sure he kept enough - or any - for himself.
This is Mister. At about 2.5 yo, he went to a new home in Ohio and lived for several years with his new flock until a dog broke into their chicken yard and he was killed in the attack.
I kept the larger rooster in this photo.