Manchester United manager Sir Alex Ferguson is tipping Rafael to become one of the world's best full-backs after the youngster signed a new four-year deal.
The 21-year-old has earned a call-up to Brazil's squad since joining United four years ago and Ferguson believes continued development will see the defender progress even further at the highest level.
"Rafael has all the attributes to become one of the best full-backs in the world and I am delighted he has signed a new contract," the Scot told manutd.com.
"The boy has developed immensely since joining United, his energy and enthusiasm are a joy to watch."
The defender has not been without some difficult periods in his first four years at Old Trafford but he has generally been on an upward curve.
Rafael thanked Ferguson for his support and voiced his desire to have more success with United.
"I love playing for Manchester United, there is a great team spirit here and a real desire to win," he said.
"My time here has been unbelievable; winning two league titles, a league cup and a Club World Cup has made me hungry for more trophies."
Although Rafael's stay at United has been extended the club have officially confirmed the release of striker Michael Owen and goalkeeper Tomas Kuszczak after their contracts expired, along with 18-year-old keepers Liam Jacob and Joe Coll.
Meanwhile, Rafael's twin brother Fabio has joined QPR on a season-long loan. The full-back, who can play on either side of the back four, has played 53 first-team matches for the Red Devils but has rarely been a first-choice starter.