Chelsea have agreed terms with Fluminense for the signing of defender Wallace who is set to become the club's first signing of the January transfer window.
The 18 year old will re-join the Brazilian side on loan until the end of the season and join the remainder of the Blues squad in the summer.
Wallace joins fellow-countryman Ramires, David Luiz and Oscar at Stamford Bridge and is expected to provide competition at full back to Branislav Ivanovic and Cesar Azpilicueta.
The transfer enhances the two clubs' working relationship with both Deco and Juliano Belletti having moved in the opposition direction in the summer of 2010.
The youngster helped Fluminense win the Brazilian league championship last season, while he also contributed to Brazil winning the South American Under-17 Championship last year and the country's fourth-placed finish in the Under-17 World Cup in Mexico.
On moving to Chelsea, Wallace said last month: "Now that I'm moving to London I'll have to learn some English but they [the Brazilian players already at Chelsea] are used to this and they will surely help me a lot.
"I used to follow the Spanish league and its big clubs like Real Madrid but now as I'm moving to Chelsea I'm following the club more closely, especially after the Champions League title.
"I watch Chelsea games whenever I can, sometimes I can't watch because I'm playing or concentrated with my team, but I don't miss a chance to see them playing on TV."
Meanwhile, Chelsea will on Wednesday attempt to avoid becoming the first Champions League holders to exit the competition at the group phase when they take on Nordsjaelland, hoping that group leaders Shakhtar Donetsk can overcome Juventus.
The club are without a win under interim boss Rafa Benitez in three games since the Spaniard took over from Roberto di Matteo and midfielder Juan Mata says the players owe the manager his first win.
"I think we will have a chance to go through. First of all we have to do our job, which is to win," said Mata.
"Hopefully Shakhtar will win against Juventus. They won against us, for example. It's not easy to play in their stadium; it's got a hard atmosphere. I still believe that we will have the chance to get through.'
"It's not going to be easy, even playing against a team we beat 4-0 in the first game. They always play good football and they have a lot of possession in all their games.
"We know the most important thing we need at this moment is to win and hopefully it will be tomorrow. We are training really hard to improve some things and just trying to be focused in every game."