Striker Milito and midfielder Cambiasso suffered thigh muscle strains whilst on international duty for Argentina as they crashed to a 1-0 defeat in Japan on Friday.
It is likely that head coach Rafa Benitez will be without the pair for the Champions League home game against Tottenham on 20 October and at least three Serie A matches against Cagliari, Sampdoria and Genoa.
The Argentines are pencilled in to return for the Champions League clash against Tottenham at White Hart Lane on 2 November.
Milito, Inter's top scorer last term, has struggled for form and fitness this term and has been eclipsed by strike partner Samuel Eto'o who has been in fine form.
The 31-year-old's absence will still be a blow although Goran Pandev is back in training after a knock.
Cambiasso has been one of Inter's most consistent performers over the years but his injury coincides with fellow midfielder Thiago Motta returning to full training after knee surgery.