Chelsea's stockpiling of young European talent has continued with the signing of Malang Sarr.
The 21-year old was a free agent having seen his contract at Ligue 1 side Nice expire at the end of June.
Despite their defensive frailties last season, Chelsea will send Sarr out on loan for the 2020-21 campaign to "gain valuable game time".
Despite his youthful age, Sarr played 119 games for Nice across four seasons having become a regular in the side at 17.
Chelsea sent 31 (thirty-one) players out on loan during the 2019-20 season, and the French U21 international will be among that number next term.
Sarr can play at centre-back, or on the left side of a defensive three and already has Europa League experience.
However, Chelsea are set to sign Thiago Silva - also on a free transfer - this summer. The Brazilian turns 36 in September and is a free agent following his release by Paris Saint-Germain.
Chelsea director Marina Granovskaia said of Sarr's signing, "The opportunity to sign Malang was one we could not miss.
"He is a tremendous prospect and we will be monitoring him closely during his loan period, hoping he will soon be back at Chelsea. We are very happy to welcome him to the club today."