Chelsea have approached Shakhtar Donetsk over a move for playmaker Douglas Costa and are prepared to up their offer to £20m for the one-time Manchester United target.
According to The Guardian, Chelsea boss Jose Mourinho is considering his options as he prepares to lose at least one first-team player this month - believed to be either Andre Schurrle or Mohamed Salah.
He wants a replacement in and has identified Fiorentina's Juan Cuadrado and Shakhtar's Douglas Costa as his two targets.
Chelsea are reportedly prepared to pay £20m for the 24-year-old, but they will need to compromise as the Ukrainian giants are holding out for closing to £30m.
Manchester United have been long-term admirers of the talented attacking midfielder, having scouted him when he was with Gremio in Brazil. He earned a move to Shakhtar in 2010, joining the club for £4.5m.
Several Brazilian players play or have played in Ukraine - the likes of Fernandinho and Willian moved to the Premier League from the country.
But United seem to have dropped their interest, leaving Chelsea free to snap him up if they're willing to meet his asking price. He has also recently admitted that he's keen to play in London.
Mourinho confirmed today that Schurrle and Salah may not be Chelsea players come the end of the transfer window.
Chelsea are under no pressure to sell, but if Mourinho wants to buy this month he will have to offload one or two first-team players to make it work under FFP.
Salah and Schurrle have not been first-team regulars at Stamford Bridge this season, and the Germany international could be tempted by a return to the Bundesliga with Wolfsburg or Borussia Dortmund.
As for Salah, AS Roma remains his most likely destination.
Chelsea play Bradford City in the FA Cup fourth round on Saturday.