Sporting paid €3m to sign Eduardo from Internacional last year, but he started only 10 times in Liga NOS and the Europa League.
The former Brazil youth international knows his future is away from Lisbon and a number of clubs are keen.
Newly-crowned Turkish champions Istanbul Basaksehir are also interested in the 25-year-old.
Another club from Turkey, Trabzonspor, held talks with Sporting over a potential deal in June.
Despite his lack of involvement, Sporting hope to net a capital gain and sell Eduardo for around €5m.