The 22-year-old Brazilian has been a regular feature of the United side at right-back throughout the calendar year. Aside from an aberration at Reading earlier this month, when he was substituted after just 31 tortured minutes, Rafael has been one of the side's most consistent performers.
Rafael told the club's website, www.manutd.com: "It's been a great year for me. I feel like I have grown up a lot and that I am maturing."
He added: "My daughter was born this year, which has helped me a lot in that way, and on the pitch I have been able to play a lot of games. So I've had a lot of good moments, not just in football, but in life this year.
"I feel more experienced and like I am growing as a player and a person. I was only 18 when I first came here, I was just a boy. Some people may think I am still young and still a boy but now I feel like I am a man.
"Playing games week-in, week-out helps you feel more comfortable and confident on the pitch and I'm pleased I've been able to do that this season."
United lead the Barclays Premier League by six points heading into the Christmas fixtures and the team are safely through to the knockout stage of the Champions League.
Rafael, who signed a four-year contract last summer, said: "My target for 2013 is like every player - we want to win trophies. When you're at this club that has to be your focus - we all want to win.
"And personally I want to play as many games as I can and be consistent in my performances.
"When you get into January you know the really important time in the season is not that far away and there will be big game after big game. Of course, every game is important but after Christmas they become massive matches."
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