The Brazilian defender helped the Reds keep a fourth clean sheet out of the six fixtures in Group A during a 1-0 success against Shakhtar Donetsk to ensure seeding in the draw in Nyon, Switzerland. The draw is scheduled for around 11:00 GMT and the ties will be played in February and March next year.
"It was important to come first in the group," Rafael told ManUtd.com. "We did the job and it was very important.
"Shakhtar worked hard and played well in the first half but we kept the ball well in the second half. Their Brazilian players have skills and it was a hard game but, in the end, it is a good result for us.
"I can remember last season when we also won the group and yet we played Real Madrid. I hope something like that doesn't happen again but we can take anyone. I've seen Manchester City won 3-2 against Bayern Munich, which is a surprise, but City finished second so we can't play Bayern yet. I think that is a good thing."
Before the draw, thoughts revert to the Barclays Premier League again and Sunday's encounter against Aston Villa. The Midlanders' home has traditionally been a happy hunting ground for United and the scene of some stirring performances.