The Tricky Trees roped in Carvalho from Portuguese giants Benfica in the summer of 2018 for a club record fee.
However, the 24-year-old has struggled to live up to his billing at the City Ground since his move and is now being linked with an exit.
Carvalho was shipped off on loan to Spanish side Almeria last season and he has only been a bit part player this season since returning to his parent club
The midfielder has only two Championship starts to his name in the current campaign, although he has had game time from the bench under new boss Steve Cooper.
Carvalho’s situation at the Nottinghamshire giants has seen him attract interest from abroad and Olympiacos are keen on him.
The Thrylos want reinforcements in midfield and are evaluating all options to snare away Carvalho to Greece.
Carvalho is down the pecking order under Cooper and it remains to be seen whether Olympiacos will hand him an opportunity to leave Forest this month.
