Ferguson has already revealed his intention to play midfielder Michael Carrick in central defence while another midfielder, Darren Fletcher, seems certain to occupy a defensive berth too.

CNN: Vidic setback adds to Man United worries

Ronaldo added a second goal after the break, while a late Robin van Persie penalty for the Gunners - after Darren Fletcher was deemed to have fouled Cesc Fabregas - was little consolation for Wenger.

BBC: Wenger rueful after 'worst night'