Kean arrived in the summer transfer window from Juventus.
But Calciomercato is reporting that Everton are being offered the chance to sign Krzysztof Piątek in the January transfer window, if they let Kean go in the opposite direction.
There are some suggestions of attitude problems for Kean, who has often been late to team meetings.
He has not scored a goal since his summer arrival.
Piatek has also slowed down at Milan, where he only has three goals in 12 games this term.