Chelsea have confirmed that Jeremie Boga has joined Serie A side Sassuolo in a permanent deal.
The 21-year-old midfielder played in the Premier League opener against Burnley last season before being sent out on loan to Birmingham City.
Sassuolo announced Boga's arrival on Saturday and added that Chelsea inserted a buyback clause in the deal.
"[Boga] helped us lift two FA Youth Cups, the UEFA Youth League and Under-21 Premier League during his time as a Blue, as well as spending time on loan with Rennes, Granada and Birmingham City," read a Blues statement.
"We thank Jeremie for his service and wish him well in his future career."
Sassuolo, who finished 11th in Serie A in 2017-18, will reportedly pay a fee in the region of £3.5m for the Ivory Coast international.