Manchester United boss Sir Alex Ferguson has revealed he's pumped his former assistant boss Carlos Queiroz for his opinion on Cristiano Ronaldo's form.

"I spoke to Carlos on Saturday morning before the West Brom game to ask him what he thought, and he felt that Cristiano was still finding it difficult to recover for a Wednesday game after a Saturday game," said Ferguson.

"He had played for Portugal against Sweden on the Saturday and Carlos said he was magnificent, unbelievable - his maturity, his decision-making, everything was at the top of his game.

"But against Albania on the Wednesday, he was a little flat because he is still trying to find the recovery thing properly.

"We are looking at the situation against Celtic because it is Saturday-Tuesday in terms of games. If we had an extra day, it would be perfect for us, but are just looking at the situation and whether we should bring in Nani for this one.

"He only played 36 minutes for Portugal last Wednesday and then 15 minutes for us on Saturday, so he is fresh."