The former Inter player Beppe Bergomi were in the studio of Sky Sport where he talked about the current formation which Mazzarri is using.
“Players like Kovacic and Alvarez have to fall deeper and help Cambiasso in the the build up-phase otherwise it’s impossible to create an attack.”
Source: fcinternews.it
It HAS to be Kovacic. Alvarez is more effective upfront