The 18-year-old has impressed for United lately and was handed a shock start against Aalborg last night.
Fergie said: “We have great hopes for the lad. He has impressed us a lot.
“Some people might have been a bit surprised I picked him over Wes Brown but I feel the boy has something special.
“Rafael has no fear of playing and has great belief in himself.
“He is only 18 but he has started very well.
“He did well against Middlesbrough last week and he has progressed again.
“He is really positive and has a great chance in the future.”