The 21-year-old has alerted a host of European clubs, particularly in Italy, following his performances for Steaua.
English club Norwich were in talks over a potential deal but pulled out when FCSB asked for €15m.
Norwich had offered £5m (€5.5m) and the valuations between the clubs were just too far apart.
Instead, Man could be off to Italy with a source describing interest from Sassuolo as ‘very serious’.
Sassuolo have had a great season in Serie A and are sitting pretty in eighth position with four games to go.
Romania international Man has the profile they are looking for, making him an ideal addition if the price is right.
Sassuolo not alone
Other clubs could also yet step forward for Man, one of Romania’s best talents of his generation.
FCSB had wanted a Liga 1 record fee of €30m at the time for their dynamic winger.
However, with the Coronavirus pandemic affecting the market they are now willing to negotiate at closer to €15m.
Man scored eight goals and delivered five assists this season for Steaua and is under contract with the 26-time champions until 2022.