Ferguson said: "There was some promising stuff the other night.
"We played really good football at times and it was interesting to play Rooney, Chicharito [Javier Hernandez] and Van Persie together. It gives us some thoughts and options for certain games.
"I think our strength is in our attacking options. I put Shinji [Kagawa] on the bench and I have got to think about [Paul] Scholes, [Ryan] Giggs and [Michael] Carrick now, which just heightens the problem about picking teams. I hope I pick the right one."