We can't take out one of the centerhalves. Rafa shouldn't play on the left instead of Evra. So yes, If Fergie wants that kind of sub, it has to be Rafael. Cruel but true.
Taking off Giggs would reduce the speed in midfield too much. Can't have Carrick and Scholes only. I think Rafael is not needed right now when Valencia might as well do the job + he's able to fill in once we attack. It's an all-in situation right now.
So now when we need energy in the midfield we have Giggs and Scholes. I love them both to bits but for feck sake they can't do the leg work needed in a game like this.