AC Milan want to sign Argentine international Crespo on a permanent basis but Mourinho, who would welcome him back to Stamford Bridge, insists they must pay a large fee or offer Shevchenko to make the deal go through. Chelsea paid £16.8million for Crespo two years ago but AC Milan have so far tabled an offer of just £5m. Mourinho also confirmed that he's looking to sign a left-back, midfielder and a striker this summer and revealed he is prepared to offer goalkeeper Carlo Cudicini a new contract to keep him at the club.