The young Brazilian found it tough going attempting to stem the flow of attacks and was eventually booked for a foul on Mesut Ozil just before the break. At the time it seemed likely Rafael would be replaced pretty quickly, but instead the United boss kept faith with the 22-year-old and his reward came in the form of a far more disciplined second-half performance.
"Rafael had an horrendous first half," said Ferguson. "He was impetuous. He tried to win the war right away, diving in at players, but he settled down in the second half. His game calmed down and he had absolutely no problems. That is a measure of the success he has had this year. He has matured terrifically well."
There is no doubt Rafael has cemented his status as United's first-choice right-back this term, but that may not mean he keeps his place for Monday's FA Cup fifth-round clash with Reading.
For Ferguson is acutely aware he made a number of people quite unhappy with his team selection in midweek.
And he is eager to ensure none of them feel left out, knowing they will all be required if United are even to get close to emulating their historic 1999 treble feat.
"We have a stronger squad now," said Ferguson. "When we went to the (Champions League) final, (Roy) Keane and (Paul) Scholes were suspended but Henning Berg was the only injury.
"I still had to pull in a player (Jonathan Greening) who had only played once or twice in the first team.
"He got a medal for being on the bench. That gives you an idea of the strength of the squad."
Paul Scholes has definitely been ruled out as he tries to find a solution to a knee injury that has kept him on the sidelines since the fourth-round victory over Fulham three weeks ago.
- Sports & Recreation