The 35-year-old scored 28 goals in 46 appearances for Manchester United during the 2016-17 campaign, but he missed the final stages of the season after picking up a serious knee injury, which required surgery.
United have opted against renewing the striker's contract for a further 12 months, although the Swede will continue his rehabilitation with the English outfit ahead of a return at the start of 2018.
A new short-term contract with the Red Devils has not been ruled out once Ibrahimovic fully recovers, although his agent Raiola has suggested that a return to Italy will be next on the agenda for the experienced forward.
"Many clubs are interested in Ibrahimovic; from MLS in the USA, but also in Italy would be possible," Raiola told Sky Sports News. "Napoli? Everything is possible, but I think Napoli will not be his next club."
Ibrahimovic, who has represented Juventus, Inter Milan and AC Milan in Italy's top flight, has also been strongly linked with LA Galaxy over the last week.