The young defender admits the excitement is growing ahead of the Emirates FA Cup fifth round tie, but believes Rovers are more than capable of giving them a tough time.
"It is going to be a really big occasion, it is going to be a tough game," Nyambe told Rovers PlayerHD
"Everyone is excited about it but we know that we have to have a good performance.
"We've caused upsets this season when we beat Newcastle so there's no reason why we can't do the same against United."
Sunday's opponents have an array of world stars, but it is one with local connections that Nyambe is most looking forward to facing - Marcus Rashford.
The two have been on opposing sides throughout their progression through the youth ranks, and the 19-year-old can't wait to face him once more.
"I've played against him back in the day for the youth teams, Under-14s, 15s and 16s.
"I didn't really come up against him as he was always in the middle and I was on the right but seeing the way he is now I'd love to play against him."
Rovers supporters are reminded that they have until close of business on Saturday to get their tickets for the match.
There are no sales on the day for the eagerly-awaited cup-tie, so fans have to get their tickets in advance. The Roverstore at Ewood Park, and the call centre will be open from 10am - 4pm on Saturday for the sales of tickets.
The Jack Walker Stand is all but sold out with only single seats remaining, fans looking to watch the match with friends will need to purchase tickets in the Blackburn End or the RFS Riverside.
Tickets are only on sale to Rovers supporters with a database history of purchasing tickets. With prices in all areas at £30 for Adults, £20 for Seniors 65+ and 18-21 year-olds, just £10 for Juniors aged 17 and under.
Rovers v Man Utd dafabet price boosts:
- Marvin Emnes to score anytime NOW 4/1 (was 10/3)
- Craig Conway to score anytime NOW 8/1 (was 13/2)
- Rovers to score first NOW 10/3 (was 13/5)
- Rovers clean sheet NOW 8/1 (was 13/2)
for these and many more odds on the match.
T&C's apply, 18+ please gamble responsibly. Odds are correct at time of publication and are subject to change.