I wonder exactly what it is that's making him so unhappy? We are overstocked and will be further when Keita arrives but Can is playing enough football and he's probably one of the first names on the team sheet right now.
I heard a while ago that he doesn't fancy the box to box role, he has the athleticism but also had dodgy knees and therefore prefers the holding role. Perhaps he is considering the pace of the game in England, especially how Liverpool play? It would consider why he's being linked with an Italian club where the game is played at a much slower pace.