Sir Alex Ferguson is learning his lesson after previously predicting a return for Owen Hargreaves in September and then in November.
The Manchester United midfielder made a tentative appearance outside for his first ball work on Tuesday afternoon but is probably still several weeks away from a return.
Said Ferguson: "It's difficult to say when he will be fit. You are not going to get an answer to that. It is a confidence to know when he is ready and that will be sooner or later."
Over to Arsenal and Arsene Wenger was left rueing more injuries as William Gallas left the victory over Standard Liege at half-time. Kieran Gibbs then fractured his metatarsal in a late, late challenge and will now miss several weeks' of football.
"Gallas has an ankle problem and a swollen eye," said Wenger. "I think he'll recover from the eye and we hope for the ankle for the Chelsea game.
"Gibbs is much more serious. He has a big hole in his leg. It was a very bad challenge from the No.22 and it was not his first try.
"Unfortunately he doesn't look too good. The vibes from the medical team were not very positive."
The Gunners are already missing Abou Diaby, Gael Clichy, Robin van Persie, Jack Wilshere, Nicklas Bendtner and Johan Djourou.
Wolves will welcome back Ronald Zubar to full training tomorrow and he could face Birmingham this Sunday.
"I think Ronald will train tomorrow, which will be good and a boost to us," said boss Mick McCarthy. "It's just a slight thigh strain, so we're hoping he'll be fine."
Martin Petrov has ruled himself out of Manchester City's weekend Premier League clash against Hull City.
The Eastlands winger is on the mend following a knee injury sustained on international duty for Bulgaria last week and Petrov's absence came as a blow to the Blues following the 30-year-old's stunning form in October.
"I am feeling better but I don't think I'll make it this week," he said on the club's official website."I am hoping that I can start training again at the start of next week."
But Robinho will be back after his three-month lay-off with an ankle problem. First-team coach Eddie Niedzwiecki told the Manchester Evening News: "Robi's looking really good.
"He had good training and good treatment while with Brazil and has come back to us looking sharper by the day.
"Things are looking very promising for him in terms of the weekend, and he should be up for selection."
Kolo Toure should also be fit despite limping out of Saturday's draw at Anfield with a back problem.
Aston Villa manager Martin O'Neill has confirmed he will not rush central defender James Collins back from a groin injury.
The former West Ham stopper has missed Villa's last two Premier League outings against Bolton and Burley with the problem.
Collins was close to returning against The Clarets before suffering a setback and O'Neill is against pushing him back early again.
O'Neill insists the Wales ace remains doubtful to face Spurs and he will make a late decision on his fitness before finalising his starting XI.
"I would say at this minute he is probably still a doubt (for Saturday)," said O'Neill. "It is a groin problem."
