Former club Roma are interested in the midfielder, who is said to be unahppy with the lack of action he's seen this season.
Zenga told Sky Italia: "Let’s remember that there are five substitutions and many matches to play.
“However, as a club, if a player were to come to me and say they’re not happy and want to leave…
“Maybe someone who’s unhappy doesn’t even train at a high level and ends up lowering the overall standard.”
Roma have already had one offer of a swap involving Lorenzo Pellegrini rejected by Inter.