Rafael has played in more first-team games this term for United than any other member of Sir Alex Ferguson's squad, featuring 21 times in all competitions, 20 as part of the starting XI and feels his development has been aided by his twin brother Fabio leaving Old Trafford on loan.
With the Brazil right-back having been so key to a Red Devils side that is through to the last 16 of the Champions League and currently six points clear at the top of the Barclays Premier League, the campaign could hardly have gone better for him.
Indeed, where Rafael is at now is exceeding his own pre-season expectations, although the 22-year-old does see himself as having evolved considerably as a player since he and Fabio arrived at United in 2008 after departing Fluminense.
"I start every season hoping to make an impression and play a lot of games, but I couldn't have imagined how well this season has gone for me," Rafael told Inside United.
"It's been great, and yes, I've been a little surprised to have played so many games.
"But I'm not a young player any more. I feel like I've developed and I want to play in every single game."
He added: "I've waited a long time for this - getting to this point hasn't happened overnight.
"I've been at this club for five years and that's a long time.
"At first, the goal was to just play one game for Manchester United. Then, when you achieve that, you set other targets.
"Now I want to play every game and become a regular in the team."
Rafael feels maturing as a person has helped him progress on the pitch, with his separation from Fabio - another full-back who can also play in midfield and signed for QPR on a season-long loan in July - an important part of the process.
Asked how he thought he had changed, Rafael joked: "I'm getting old!"
"No, I think this is just a natural development; it's bound to happen when you play more games and have more experiences.
"My daughter has also helped me - (being a father) has settled me down a lot. When you're a dad you have to be mature.
"Also, I think splitting from Fabio has been a good experience.
"At first I was sad, but I've come to see that it's made me grow up a lot. I've had to change and be more responsible."