Forest are continuing their summer spending splurge and have agreed a fee with Bundesliga outfit Stuttgart for the signature of the midfielder.
They are now moving to put the finishing touches to the capture of the 24-year-old and push the deal over the line.
It had been thought that Mangala would undergo his medical in England, but it has now emerged it will take place in Greece.
Mangala will fly into Athens and have his Nottingham Forest medical on Tuesday afternoon in the Greek capital, according to Belgian journalist Sacha Tavolieri.
If the medical check-up goes well then Mangala will board a plane and head to England to link up with Nottingham Forest.
The 24-year-old midfielder will be looking to hit the ground running in the Premier League as he joins Steve Cooper’s newly promoted side.
Mangala has been capped twice at senior international level by Belgium and caught the eye with his performances in Germany at Stuttgart.