Chelsea has completed the signing of
The 20-year-old joins the European champion in a deal reported to be worth £25 million ($37.57 million).
Oscar in action:
He is part of
Oscar, full name Oscar dos Santos Emboaba Junior, is a product of the Sao Paulo youth set up.
He left the capital for Internacional in December 2010 and has played at every level of international football from Under-15 to Under-20.
His Brazil debut arrived in September last year when he came on as a substitute in a 0-0 draw with Argentina, and he has scored once in six caps.
Capable of playing as an attacking midfielder or winger, he is viewed as one of his country's most exciting talents.
Marseille fullback Cesar Azpilicueta has confirmed he is also on Chelsea's radar.
"It is flattering when you have clubs such as Chelsea interested in you, but there are other clubs interested as well," the Spaniard said.
Midfielder Kevin de Bruyne looks set to spend another season on loan away from Chelsea after Werder Bremen revealed negotiations over the 20-year-old are being held.
Chelsea has also seen bids for other signings rejected this northern summer, including Wigan Athletic midfielder Victor Moses.
There are widespread reports the Blues have reopened negotiations over the 21-year-old, who is available for a £10 million ($15.03 million) package.
West Ham United has completed its first transfer of the post-season after signing Romania international fullback Razvan Rat on a free transfer.