Chelsea have sold defender Filipe Luis back to Atletico Madrid, the Premier League club announced on their website.
The 29-year-old Brazilian, a £16million signing from Atletico last summer, returns to the Spanish capital after making only 26 appearances for the Blues.
"We wish him all the best for the future," a club statement read.
Luis has signed a four-year-contract with Atletico for a reported fee of £11million.
Of his 26 appearances for Chelsea, only nine of them were starts in the Premier League after he struggled to displace Cesar Azpilicueta at left-back.
Luis returns to Spain with Premier League and Capital One Cup winners medals and scored once during his year at Stamford Bridge.
Meanwhile, MLS side Montreal Impact have signed former Chelsea striker Didier Drogba.
Drogba moves to North America following his second spell at Chelsea, where he won the league title last season. The 37-year-old Ivory Coast forward signed with the Chicago Fire, who then sent him to the Impact for general and targeted allocation money.
Drogba is expected to join Impact later this week after receiving his international transfer certificate and work visa.
"It's an honor to welcome Didier Drogba to the Impact," club president Joey Saputo said.
Drogba scored 163 goals and won four Premier League titles in two stints with Chelsea. He had the winning penalty kick as Chelsea won its first Champions League crown in 2012.
The Impact had been seeking an elite forward since Italian veteran Marco Di Vaio, who joined the club as a designated player in its first MLS campaign in 2012, retired after last season. "We are very excited and thrilled to add to our roster a player with an exceptional career," technical director Adam Braz said.