Atletico Madrid will reportedly try to tempt Chelsea with Diego Costa or Koke in order to land Belgian goalkeeper Thibaut Courtois.
The 21-year-old has spent the last two-and-a-half seasons on loan at the Vicente Calderon, where he has established himself as one of the best young goalkeepers in Europe.
According to The Mirror, the Spanish side are keen to secure him on a full-time deal and are prepared to part with either Costa or Koke to make it happen.
The Brazilian forward, who has chosen to represent Spain at international level, has been in fine form in La Liga this season, scoring 19 goals in 17 appearances for Los Colchoneros.
Liverpool and Arsenal have both been linked, but the 25-year-old, valued at around £20m, has always made clear his desire to stay with Altetico.
Meanwhile, Koke has also become an integral member of Diego Simeone's team and is said to be of interest to Premier League champions Manchester United.