Rafael arrived at Old Trafford with twin brother Fabio as an 18-year-old in 2008, having been spotted in Hong Kong three years by then academy director Les Kershaw playing in a youth tournament with Brazilian outfit Fluminense.
He made such progress in that first season that Sir Alex Ferguson named him on the bench for the Champions League final defeat to Barcelona in Rome.
Since then though, Rafael has struggled to match those early days.
A red card in a European tie with Bayern Munich that seemed to be won and was eventually lost highlighted his impetuosity and when United reached the final again a year later, it was Fabio who got the starting berth.
Slowly though, Rafael has rebuilt his reputation and started to correct the faults in his game.
He emerged a better player for his Olympic experiences with Brazil and despite Fabio's departure on loan to QPR this summer, Rafael has excelled at a time when he has largely been United's only fit right-back, hence his 19th appearance of the campaign in Wednesday night's 1-0 win over West Ham.
"Rafael came into the team at 18 and made a lot of mistakes," said Sir Alex Ferguson. "He was very rash.
"But we invested in him for our future and he is showing that maturity now."
Defensive colleague Jonny Evans has gone even further, indicating new Brazil coach Luis Felipe Scolari should be casting a close eye on a player who, to date, has made just two appearances at senior level in addition to his performances for the silver medal-winning Olympic side.
"Rafael has been outstanding all season," said the Northern Ireland international.
"He has had to play there quite a lot because there has not been anyone else challenging in that position but his energy at right-back is really good.
"He really sets the tone and is a credit to himself.
"Everyone probably thought it would be a bit tough for him with his brother going away but he has got his head down and worked really hard.
"He is one of the best right backs in the world."
Rafael and Evans were part of a defence that secured only its fourth clean sheet of the season against the Hammers.
It was one of the few plus points from an otherwise disappointing evening, when the Red Devils failed to capitalise on the start given to them by Robin van Persie, who scored the quickest Premier League goal of the season.
Not that Michael Carrick is underestimating the benefits of such shut outs as the days tick down to the first Manchester derby of the season at the Etihad Stadium on December 9, which looks increasingly like a meeting between the two sides who will once again scrap it out for the title given Chelsea's present troubles.
"It was a long way from a classic," said Carrick.
"The biggest plus was the clean sheet, which at least gives us something to build on.
"We had a spell a few years ago when we really started games well and could have killed teams off.
"We want to try and get back to something near that because Old Trafford is a difficult place to come when you go a goal down."
Not everything in Sir Alex Ferguson's garden is entirely rosy though.
Paul Scholes' availability after suspension presents a selection dilemma for Saturday's trip to Reading as, whilst the veteran midfielder has come under fire for his recent performances, his replacement on Wednesday night, Anderson, did not get through the full 90 minutes, signalling to the bench before the end he was too tired to continue.