Inter Milan boss Jose Mourinho admitted that his side could be facing a defensive crisis when they meet Manchester United in the Champions League in midweek. The Portuguese tactician had defense duo Marco Materazzi and Nicolas Burdisso taken off the first half of Saturday's 2-0 Serie A win at Genoa after picking up respective injuries. Moreover, Inter are already in major doubt of having first-choice pair Christian Chivu and Walter Samuel fit before Wednesday. "We have faith for the game in Manchester even if I won't be able to sleep because we'll have lots of problems in defense against very strong, attacking opponents," Mourinho told Sky television. "In defense, without Materazzi and Burdisso, without me being able to make any more changes, the spirit of the squad has come to the fore." Amid his injury problems, Mourinho implied that he could be forced to deploy midfielder Esteban Cambiasso as center-half, alongside Ivan Cordoba. "Cambiasso played magnificently as a centre back and on the field he has been a leader," added the former Chelsea boss. Inter were held to a goalless draw by United in the round of 16 first leg as they will face a tough task not to concede against the European champions at Old Trafford.