I would start training this cockerel right now. I don't make pets of my cockerels (rooster under 1 year of age). I make them keep their distance and respect my space. If one is between me and were I want to be, I will walk in a straight line to get there and he will move out of my way. I will move him away from feed and water sometimes, just because I can. I will walk toward them until they move away, just to remind them that I am the boss. If one comes toward me, I will make him back up. Sometimes I will just walk right through them to make them a little wary of me. I act with confidence around them all, and don't let any of them back me down, chase me or approach me. I have been raising cockerels like this for some time, and have yet to have a human aggressive rooster. Let him do his job, protecting the flock, and don't make a pet out of him.