The Bantams will take on Gus Poyet's Black Cats in front of a sold out Valley Parade for a place in the quarter-finals of the world's most famous domestic cup competition.
On top of the extremely high demand for match tickets from City supporters, the nation's media have been keen to get involved in the action, especially following the Bantams' stunning victory at Chelsea in the previous round.
Having defied all the odds to defeat Jose Mourinho's superstars at Stamford Bridge last month, Parkinson admits this weekend's tie is a bit of an added extra for his players and the club.
Given the array of talent Sunday's opponents possess, Sunderland will understandably start the match as favourites to progress but Parkinson says City will still be giving it their all once again.
Parkinson said: "We were so pleased to pick up a terrific win over Milton Keynes Dons on Monday partly because it will enable us to really enjoy the build up to this tie.
"It is important that we all enjoy the build up to this weekend. Everybody connected with the club has worked really hard to get to this stage of the competition.
"If we are being honest, this Sunday's match is a bit of a bonus for us.
"When we defeated Millwall in the third round replay to earn our match at Chelsea, I don't think anyone expected us to actually go there and get through.
"We will go into Sunday's game with nothing to lose and everything to gain. This is another tremendous challenge, and we will approach it in a positive fashion.
"Whatever the score is come the final whistle, if we have put in a performance that truly reflects what Bradford City, our supporters and the city of Bradford itself are all about, then we can't ask for anymore from the players.
"I hope the supporters enjoy the day, soak up the atmosphere of a full house, and help to make it an occasion to remember."