United boss Alex Ferguson was clearly fuming with his player afterwards, despite the Reds' 4-1 win.
Now he will be hit with a fine of two weeks' wages for the straight red card.
Ferguson said: "The game was marred by the immaturity of Nani.
"He bought the challenge from their player and retaliated. He will learn from that.
"I don't think the referee had any option. It was the linesman's say-so anyway. The linesman saw it clearly.
"Nani has retaliated and will now miss the Wigan game and the first two of next season. We will deal with it."