Tiémoué Bakayoko has returned to AS Monaco on a season-long loan, the principality club have announced.
The 25-year-old has come back to the Stade Louis II from Chelsea, with the agreement including an option for Monaco to sign the once-capped French international midfielder on a permanent deal at the end of the campaign.
"I am delighted to be back at AS Monaco, a club where I have some fantastic memories," said Bakayoko, who spent three years at the club in his first spell and was a key part of Leonardo Jardim's Ligue 1 title-winning side in 2017.
On the back of that campaign, he joined Chelsea where he was a regular in his first season at Stamford Bridge, helping the London side win the FA Cup. However, he spent last season on loan at AC Milan and appeared not to be in new manager Frank Lampard's plans on his return to Chelsea.
He added: "I have had two really good experiences at Chelsea and Milan. Now I hope to integrate as quickly as possible into an environment I already know. Hopefully I can bring something to the squad and help us have a good season."
Bakayoko is Monaco's ninth signing in total of the summer transfer window. Adrien Silva and Islam Slimani of Leicester City have also arrived on loan. Meanwhile, the arrival of teenage midfielder Arthur Zagre from Paris Saint-Germain on Friday followed permanent deals for Montpellier Hérault SC pair Benjamin Lecomte and Rubén Águilar, Henry Onyekuru from Everton, Wissam Ben Yedder from Sevilla and Chilean defender Guillermo Maripán from Alavés.