Duncan, 23, moved to Inter Milan in 2010, but after two years out on loan at Livorno, it was clear that he wouldn't be making the grade at Inter, and he was moved on to Sampdoria in 2014.
Now with Sassuolo, who have the option to purchase him for just £4.7m, Duncan has been thriving, and hit the headlines with a stunning goal in the 2-0 win over AC Milan last week.
The Ghanaian's performances have now triggered interest in his signature, with Calcio Mercato suggesting that Sassuolo will activate that £4.7m purchase clause, before selling him on for a major profit this summer.
It's claimed that Premier League rivals Tottenham Hotspur and Arsenal are leading the race to sign Duncan this summer, with Sassuolo seeking a fee in the region of £11.7m to sell one of their most prized assets behind forward Domenico Berardi.
A powerful, athletic box-to-box midfielder, the nine-cap Ghana international would add some physicality to either Spurs or Arsenal, whilst given that he turned 23 today, he has years ahead of him and plenty of potential to be tapped into.
Spurs have lacked the box-to-box qualities of Mousa Dembele when he has suffered through injury this season, and Duncan could be the man to offer similar qualities behind the Belgian, whilst Arsenal are often criticised for their lack of physicality in midfield - making Duncan potentially ideal for either side.
Would Duncan be a good signing for Spurs or Arsenal?