The Red Devils are currently eight points adrift of leaders Chelsea in the table following an indifferent start to the campaign.
However, Rafael is confident that United's star-studded squad can be crowned champions once they get to grips with new manager Louis van Gaal's coaching methods.
"If we start to understand the way of playing, like we are doing, and when the results are positive, everything starts to run smoothly and for sure we have chances to win the title," the Brazil international told Perform.
"We will have three difficult games - against West Brom away, after this we face Chelsea, the actual leader, and then Manchester City in their stadium. These games will be very important for us.
"We need to think about these three games and if we win we will be close to the leader, probably in second place, so we need to be positive and try to win these three matches."
United continue their league campaign on Monday night when they face West Bromwich Albion at The Hawthorns.