Villas-Boas was quick to leap to the defence of his player, and while admitting some of his previous booking have been warranted, insisted he had been hard done to on Wearside.
Villas-Boas said: "It's difficult for the referees, there's no question about it, but today was a big mistake.
"Sometimes we have to give a little bit of comfort and credit to the player because he is being chased now and it's a little bit unfair what he is going through, particularly because he misses a game when he was going to be the clear-out for the yellow cards.
"It's just a consequence of his pace, his ability his skill. People don't want to stop him in various different ways, sometimes they do it in a proper way, sometimes they have to foul.
"I think he understands, as I was saying, that it's difficult for the refs to judge, but today was a mistake and the team is penalised for the game against Reading."