Actually, those emerging feathers are the beginning of his saddle. Some cockerels mature earlier than others and this guy is getting his rooster feathers.The gender feathering of pointy hackle and saddle feathers doesn't show up till about 12 weeks of age. Younger birds won't show those clues.
There is also red over wings (in a bird that isn't red to begin with) usually shouts COCKEREL. Like the bird in the above photo.