Vidic to return, Nani setback
Vidic has been out since September after undergoing knee surgery but United manager Sir Alex Ferguson revealed on Friday his captain had returned to training and an appearance against Cluj was a possibility.
"It would be nice for him to play on Wednesday," said Ferguson. "We are not afraid of that."
However, there was less good news about Portugal winger Nani, who has been missing since the beginning of the month with a hamstring injury.
"Nani is going to be out for a longer spell, possibly another four or five weeks," said Ferguson.
The United manager also confirmed Antonio Valencia would miss Saturday's trip to Reading with a hip injury.
The news about Vidic raises the tantalising prospect of the Serbian getting a competitive appearance under his belt prior to the Manchester derby at the Etihad Stadium on December 9.
Vidic has endured a torrid 18 months. After suffering a calf injury that kept him out for over two months at the beginning of last season, the 31-year-old then ruptured cruciate ligaments against Basle in December that prevented him from playing again in the entire campaign.
Vidic returned in pre-season but after only five games he complained of feeling tightness in the knee again and after a further examination was forced to undergo surgery in the middle of September.
"He has started training, which is good news," said Ferguson.
"He has not been involved in the real competitive part but he has done OK.
"For the last year-and-a-half he has probably only played 10 or 12 games (13) or something like that.
"The best way is for us to leave it to 'Vida' himself. He has the experience to know what is best for him and when the time is right for him to come back into the team.
"He would be short of match practice but I wouldn't be averse to playing him on Wednesday."
Vidic will not face Reading though, when Rio Ferdinand will return after being rested for the midweek win over West Ham.
Paul Scholes sat out that 1-0 win through suspension after collecting five bookings, although Ferguson did not seem too concerned about that.
"It was quite late for Paul to be getting suspended," said the Scot.
"It's usually October."
Ferguson confirmed Ryan Giggs had sat out the Hammers encounter with a slight hamstring strain but was available for the Madejski Stadium encounter.