The 24-year-old has been on the fringes of the Nottingham Forest squad this season and has only featured seven times in the Championship.
The midfielder has been looking to move on from the Championship club this month and his agent has been looking around for opportunities.
And it has been claimed that Carvalho is set to move to Greece in the ongoing transfer window.
Olympiacos are close to working out a deal to sign the Portuguese midfielder this month.
The Greek giants are in talks with Nottingham Forest and are looking to take a deal over the line to sign the 24-year-old.
Carvalho still does not have permission to travel to Greece for medical and complete the formalities of the move.
But the negotiations are on the right track and all sides are moving towards the direction of a deal.
The midfielder is hoping to move to Greece soon and join Olympiacos from Nottingham Forest in the coming days.