Ryan Giggs says Manchester United's players and fans must forget the distractions around tonight's Carling Cup second leg derby match and focus on reaching Wembley.

Giggs, speaking ahead of what could be a volatile match given the events on and off the field during the first leg – which today led police to make more arrests – said fans should focus on the bigger picture.

"Of course, it's a derby but it's also a cup semi-final with a place at Wembley at stake and a trophy at the end of it. We're the holders and we want to defend our trophy."

City take a 2-1 lead into the match, and Giggs believes home fans have a key role to play in turning the deficit round.

"They are going to play a massive part. It was a great atmosphere at Eastlands and we need them to get behind us again because it really does make a difference. It's not often you play City in a night game – it'll be like a European match in some respects which is obviously something we're used to and something which we usually thrive on."

Guardian.co.uk