Sir Alex Ferguson is ready to rule Nemanja Vidic out of Sunday's Manchester derby after declaring his captain is unlikely to be fit to face Cluj on Wednesday.
The Manchester United manager said the centre-back needs to play against the Romanian champions if he is to take on Manchester City in the Premier League summit clash.
The Serb has been out since September with a knee injury but has returned to training and Ferguson said on Friday that he could make his comeback against Cluj.
But Ferguson said: "I don't think he will play. He feels he needs another a few days' training so he won't be available. But he's not far away now. He is training well now but I think another few days will bring him on better.
"If he doesn't play on Wednesday there is no chance of playing in the derby game. Playing on Wednesday would have been a bonus for us and we could have taken it on from then."
However, Ferguson said Shinji Kagawa is in contention for a shock return against City after a knee problem.
The Japan international has not featured since October's 3-2 win over Braga but Ferguson added: "Kagawa has started running. I don't think he will make it but maybe he could make the bench."
With United having already qualified for the last 16 of the competition as group winners, Ferguson is set to rotate. "We will rest some players as we did against Galatasaray," he said.
However, Ferguson insisted Wayne Rooney will start against Cluj to build up his match fitness and praised the England international for his performance on the right wing in Saturday's 4-3 win at Reading.
"Wayne needs to play in a lot of games to get his match fitness," he said. "He is a strongly-built lad and when he misses two games, he needs three to come back. That is the way he has always been. On Saturday without question it was his best performance of the season. He will play tomorrow night and hopefully that will bring him on further.
"Nani and [Antonio] Valencia are still out and that is why I played Rooney wide right on Saturday. He was fantastic."
Ferguson insisted the derby will not dictate his selection for the Cluj match.
He explained: "I am not thinking about the Manchester City game, I am thinking who needs a game."