Rooney claims the United players did not know he was back until Scholes turned up in the dressing room.
United managed to beat rivals City 3-2 away at Eastlands in the FA Cup on Sunday.
Rooney said: “It was a bit of a shock about Scholes – we didn’t even know until we were in the dressing-room.
“But it’s great to have such a quality player coming back.”
