The Italy international, who had fallen out of favour with Blues boss Thomas Tuchel, will spend the 2021-22 campaign at the Groupama Stadium
Chelsea full-back Emerson Palmieri has completed a loan move to Ligue 1 giants Lyon.
Emerson, who initially joined Chelsea from Roma in 2018, has struggled for regular minutes throughout his time at Stamford Bridge, and the decision has now been taken for him to head out on loan.
Lyon have snapped the Italy international up for the duration of the 2021-22 campaign, and they also have the option to purchase him outright next summer.