Sassuolo chief Giovanni Carnevali has confirmed Jeremie Boga's contract carries a Chelsea buy-back clause.
Boga spent nine years in West London, joining Chelsea's academy in 2009, and won a number of youth trophies including two FA Cups, the Development League title and the UEFA Youth League.
Chelsea ensured there could yet be a future at the Bridge for Boga after inserting a clause in his Sassuolo transfer allowing them to re-sign him for the same £3.5m they sold him for.
And Carnevali has now confirmed a deal could indeed happen at the end of the season.
He told Goal: “Chelsea can redeem Boga in June. We have a great relationship with the club and we already met them before Christmas – also for other business.
“They can take him back but we can also re-sign him, everything is open."