SIR Alex Ferguson will aim his big guns at City on Wednesday after United's FA Cup humiliation against Leeds. The Reds boss had planned to use the third-round tie as a warm-up for the Carling Cup semi-final first leg against the Blues. And he was intent on sticking by his youngsters for the clash against Roberto Mancini's side. But the FA Cup flops have blown their derby chances by losing 1-0 to the Yorkshiremen. It is the first third-round defeat of Ferguson's 23-year Old Trafford career - and United's first opening-round failure since 1984 when Ron Atkinson's holders were dumped out at Dean Court by Bournemouth. And it is going to prove costly for many on duty against old foes Leeds. "You have to get over these kind of results quickly. We have a semi-final on Wednesday night and a lot of these players today won't be playing," said a stunned Sir Alex. Performance "You have to view that performance in its right light and make sure we are ready for Wednesday. I had a team in mind but there maybe one or two changes now." Leeds created the shock of the round with Jermaine Beckford's 19th minute winner proving enough to ease past United. Ferguson was clearly staggered by the Reds' woeful effort. "I didn't expect that. Our preparation for the game was very good. I am shocked by the performance," he said. "We didn't start right and Leeds did. They got their goal and it was something to hold on to. They fought like tigers and we expect that like any team coming to Old Trafford in an FA Cup tie. It is one of these things. We are human beings and they can always surprise you but we didn't expect that today. "I don't think any of them can say they had a good day. Only Antonio Valencia when he came on and we eventually got the ball to him, which took about ten minutes, only he can say he had a good performance. "We spoke about Beckford's pace up front and we were caught napping. It is a bad goal for us to lose. "But the whole performance in the first half was bad. We never got going." Will United bounce back against City? Have your say.