We all know just how unreliable Chelsea's defence has been this season. The Blues have been about as leaky as they ever have been in the Roman Abramovich era. Frank Lampard's men have barely impressed on that side of the pitch since the restart, with catastrophic showings against West Ham and Sheffield United still fresh in the memory, and the boss knew that Manchester United - probably the Premier League's most in-form side - could cause him real problems in Sunday's FA Cup semi-final clash....