Chelsea have completed the loan signing of Radamel Falcao from Monaco, the club have confirmed.
Falcao returns to the Premier League after a spell at Manchester United last season.
Croatian midfielder Mario Pasalic has also left Stamford Bridge to join Monaco on a season-long loan as part of the deal.
Monaco claim in a statement posted on their website Chelsea have the option to buy the striker at the end of the loan deal.
"I am very happy to be joining Chelsea and can't wait to start training and help with our aim of retaining the league title and being successful in Europe," Falcao told the club's official website.
The Colombia international scored just four goals for United last season following his move on transfer deadline day in September. That poor return that saw the club refuse their option to sign him on a permanent deal for £43.2m
Jose Mourinho is hopeful he can help resurrect the career of a striker once regarded as one of the best on the planet.
"If I can help Falcao reach his level again, I will do it," the Chelsea boss said in June. "It hurts me that people in England think that the real Falcao is the one we saw at Manchester United."
20-year-old Pasalic moves in the other way after impressing while on loan at Elche in Spain last season.
The midfielder made his move to the Premier League side from Hajduk Split in July 2014 but less than two weeks later, he left Stamford Bridge to complete his season-long move to Elche.
After impressing in Spain last season, the Croatia international travelled to Monaco on 2 July to sign a deal with the Ligue 1 club, with his agent Vincenzo Cavaliere posting the contract signing on his Instagram account.
"Mario Pasalic starts a new adventure in AS Monaco! Big important step in his career. Good luck my boy," he wrote.