Bacca left Sevilla for Milan in 2015 and has scored 31 Serie A goals.
He won the Europa League twice at the Ramon Sanchez Pizjuan and Bacca's representative Sergio Barila told AS: "It is now well known that Carlos wants to return to Sevilla.
"He had a splendid personal and sporting experience in that city, which is why he wants to return. This is an important year for players, that of the World Cup, so he needs to play in order to take part.
"He is in good shape physically and ready for a great season.
"When Bacca arrived at Milan, he signed a five-year contract and had every intention of seeing it through to the last day of that agreement.
"Unfortunately, there was a change at the helm and now the Rossoneri have other ideas. The best thing to do would be to find a solution that makes everyone happy."