Chelsea have allowed Malang Sarr to join Monaco on loan with an option to buy.

The 23-year-old centre-back will move to the Ligue 1 club for the 2022-23 season, with Monaco then able to make the arrangement permanent for a reported £12.7million.

Monaco's purchase option could become mandatory if certain conditions are met, according to widespread reports.

Sarr joined Chelsea on a free transfer in August 2020 but was soon sent out on loan to Porto, where he made 19 appearances across all competitions.

He returned to Stamford Bridge for the 2021-22 season and became a member of the first-team squad, playing 21 times on all fronts, though only eight of those were in the Premier League.

In joining Monaco, Sarr returns to Ligue 1 after a two-year absence having previously been regarded as one of the most promising young defenders in Europe during his breakthrough as a teenager at Nice.

Sarr is Monaco's fourth signing of the window after Takumi Minamino, Breel Embolo and Thomas Didillon.

Monaco saw their Champions League qualification hopes ended on Tuesday when a 3-2 defeat after extra time away to PSV saw them suffer a 4-3 aggregate loss in the penultimate stage of qualifying.