Atletico Madrid are said to be "increasingly confident" that they are on the verge of securing a deal for Chelsea outcast Diego Costa.
The 28-year-old spent the summer on the hunt for a new club following Blues manager Antonio Conte's decision to drop him from the first team, but his preferred option of a return to Atletico was not possible due to their transfer ban.
The La Liga side will be able to register new players from January 1, however, and are seeking to secure the services of Costa in an agreement that will become effective when the winter transfer window opens.
Costa is believed to be in the Spanish capital helping to push through the deal and, according to Sky Sports News, Diego Simeone's side believe that they have "made a breakthrough" in negotiations.
The two clubs have been haggling over the size of the transfer fee, with the Blues demanding £50m and Atletico thus far having reportedly only offered £30m.
Should the deal go through, Costa has been earmarked for a potential short-term loan move to Saudi Arabian side Al-Hilal for the next few months.