As long as he can suck, and you think he'll be able to graze, he should be ok.
I had a lamb one year, who on first sight, had a deformed ear. But when you investigated it, there were little teeth there! It's as though she was supposed to have a twin and this was all that had come of the second one. The ear was somehow fastened to her throat, so that when she drank, some milk came out of her ear.
But for all that, she was a happy little thing, her mother liked her, and she thrived to butcher's weight.