The central defender was found guilty of a number of crimes when playing in Spain but has avoided immediate further jail term following a court hearing.
Portuguese outlet Record cite reports from local TV station TVI24 that the newly crowned Portuguese champions will sign Semedo in a deal worth €7m.
Semedo has a contract with the Greek club until June 2023 but now he looks set to return to his home nation, where he began his career with Sporting CP.
Semedo signed for Villarreal from Sporting CP in the summer of 2017 but played just five games for the club and spent the 2018/19 campaign out on loan spells at Huesca and then Rio Ave, before joining Olympiakos permanently last year.
The defender had then been suspended without pay by Villarreal and the club had been actively trying to sell him since, before his move to the Greek side last summer.