Chelsea have completed the signing of Joao Felix on loan from Atletico Madrid.
Felix joins the Blues on €11m (£9.69m) loan fee plus the Premier League side taking care of his full wages.
Atletico have said Felix has agreed to extend his deal with the Spanish club by one year taking his deal up until June 2027.
On the loan move to Chelsea, Felix told the club's official website: "Chelsea is one of the great teams in the world and I hope to help the team reach their objectives, so I am very, very happy to be here and very excited to play at Stamford Bridge."
Felix travelled to London on Tuesday to undergo a medical ahead of joining Chelsea for the rest of the season.
The 23-year-old becomes Chelsea's fourth signing of the month following the arrivals of Benoit Badiashile, David Datro Fofana and Andrey Santos.
Felix joined Atletico from Benfica in a €126m (£111m) deal from Benfica in 2019.
The LaLiga side have been prepared to let Felix - who has five goals and three assists in all competitions this season - leave on loan in January because of his difficult relationship with manager Diego Simeone.