But should a deal be struck before the market shuts next week, don't be surprised if Chelsea confirm another right-back has been signed in parallel to the Spain international.
Sources in Brazil are convinced Chelsea are ready to trigger the option they have on Fluminense fullback Wallace. Concerned over growing interest from Italy, Blues football chief Michael Emenalo is prepared to lock in the 18 year-old before loaning him back to Flu for the foreseeable future.
"About Wallace, there are many queries and a few proposals," revealed Flu president Peter Siemsen.
"However, we do not want to listen to them at the moment. Our focus now is to invest in the player, keep him and get results with him."
That support is being repaid, with Wallace now a first-choice for Flu coach Abel Braga.
Braga's concerns over the sale of Mariano to Bordeaux have been quickly abated by the emergence of Wallace. Even the signing of Bruno from Figueirense has not threatened the teenager's place in Braga's first team plans this season.
"This kid (Wallace) has an extraordinary future ahead of him," declared Braga. "He is a replica of Mariano. Though with a detail: he does not have the personality of Mariano - yet.
"But in the attacking third of the field, his level of crossing is superior to Mariano.
"So in this position, we're very happy."
Chelsea negotiated an option for Wallace two years ago as part of Deco's move to Flu. While the Portugal international signed for the Brazilian giants on a free transfer, he still had a year to run on his Blues contract and the Londoners agreed to release him in exchange for first refusal on Wallace.
The teen admits playing in the same team as Deco is something special for him.
"Deco is my idol. I hope one day to reach his level, though I know I have a long way to go," he says.
"I think I have a game somewhat similar to that of Mariano, in terms of speed and the way we both like to sprint forward."
Wallace knows all about Flu's agreement with Chelsea and is happy with the situation.
"This is nothing new for me. I know I can handle it. Since playing for Brazil's youth teams, I've had interest from clubs in Europe. I'm focused on Fluminense. I'm calm about it. My focus is only on Flu."
Wallace's agent is in regular contact with Chelsea and makes sure the youngster and his family are always up-to-speed on the European champions' interest.
Frederico Morais revealed: "At this moment, he's happy with his progress - and Fluminense have no interest in selling him. He has not signed anything with any European club. Proposals arrived, but all were dismissed by Fluminense.
"Everything about the enquiries and proposals are passed onto his family. He is not lacking at all in knowing what is going on. He wants to stay with Fluminense and will only leave once he and his family give an official 'OK'."
Emenalo's plans of signing Wallace and immediately loaning him back to Flu appears the ideal scenario for all parties.
As Morais admits: "Wallace and I have talked about Europe, but agreed that he will be best served by staying in Brazil. He now needs to develop more.
"He actually already has a lot of experience for a player of only 18 years of age. We will consider proposals only when it is the right time."