Sir Alex Ferguson has confirmed he expects Owen Hargreaves to be out of action for up to five weeks with the hamstring injury he suffered against Wolves on Saturday - and also ruled Ryan Giggs out of Wednesday's Manchester derby.

Making his first senior Manchester United start since September 2008, Hargreaves lasted just five minutes before he pulled up indicating he had suffered a problem and had to be replaced by Bebe. Now Ferguson has revealed the 29-year-old will be out of action until the middle of next month.

"We were at the stage where we knew Owen's knee was okay," Ferguson told Key 103. "His training performances for eight or nine days previously had been terrific. He had done really well, which is why we took the chance. But maybe the tension in the build-up for the lad was too much and he suffered because of it."

As soon as Hargreaves came off on Saturday, Ferguson knew he would play no part against City, but the loss of Giggs is a major blow.

The veteran Welshman was hoping to make a record 34th derby appearance at Eastlands but after feeling the hamstring injury that has kept him on the sidelines for all but one of United's last nine games in a session just prior to Saturday's win over Wolves, Ferguson has reluctantly ruled Giggs out of his plans.

"Ryan is out," said the Scot.

The news on Nani was not much better either.

Although there is an outside chance the Portugal winger may recover from the groin injury he suffered in last week's Champions League triumph over Bursaspor, Ferguson is dubious about Nani's prospects of facing City.

"Nani is doubtful," said Ferguson. "At this stage it doesn't look as if he will make it.

"It is not a great position for us to be in. We are counting heads at the moment."