Furious Manchester United manager Sir Alex Ferguson threatened to wield the axe after his star-studded side slumped to a shock FA Cup defeat against fallen giants Leeds.

United were beaten 1-0 by third-tier Leeds in the third round at Old Trafford on Sunday and Ferguson has pledged to shake things up when his team faces Manchester City at Eastlands on Wednesday in the League Cup semi finals.

"We have a semi-final on Wednesday and a lot of these players today won't be playing. You have to view that performance in the right light. But we have to get ready for Wednesday now," said the United manager.

"I had the team in mind but there may be one or two changes now."

Ferguson's mood was not helped by the mystery surrounding his defender Nemanja Vidic who pulled out of the Leeds game after claiming he felt an injury during the warm-up.

The United manager reacted angrily when asked about his experienced centerhalf. "I couldn't tell you what the situation is with Nemanja," he said.

But Ferguson was far more forthcoming when asked about the performance of his side after he had overseen his first FA Cup defeat against a team from a lower division, with Leeds, the third division leaders, winning thanks to striker Jermaine Beckford's 19th-minute goal.

"I didn't expect that," Ferguson said. "The preparation was very good. I was shocked at the performance. We didn't start right and Leeds did start right. It's a disappointment. Human beings can always surprise you but we didn't expect that.

"I don't think any of them (United players) can say they had a good day. Only Antonio Valencia when we got the ball to him but it took us about 10 minutes to do that."

Beckford scored his 20th goal of the season after running on to a 50-yard ball from Jonathan Howson, outpacing United defender Wes Brown and sliding a shot past Tomasz Kuszczak.

"Yes, we spoke about it before, Beckford has got a lot of pace," said Ferguson. "They were caught napping. It was a bad goal for us to lose but the whole performance from us was bad in the first half. We never got going and the quality of passing - the whole performance was bad."

He said: "You always expect us to get a goal at Old Trafford, the intensity of the game improved a little bit.

"We had a lot of chances in the box but we didn't take them."

Ferguson also risks fresh disciplinary action by the Football Association with a bizarre blast at referee Chris Foy after his side's shock loss.

Ferguson is already under a two-game suspended sentence until the end of next season for his remarks concerning referee Alan Wiley's supposed lack of fitness, made earlier this term.

And the FA could well take a dim view of Ferguson's amazing complaint that Foy "only" played five minutes injury-time at the end of his team's stunning loss. "The referee gave five minutes of injury-time. That is an insult to the game and to the players out there," Ferguson said.