Chris Wilder hopes to catch Leicester City on an off day at the King Power, but acknowledges the Foxes are big favourites ahead of Friday's fifth round tie.
Speaking about the challenge which will face his side, Wilder remarked: "We have to be prepared not to have a lot of the ball, we'll have to be nice and solid and we might have to change our approach slightly.
"I'm not going to be embarrassed about that because we're facing a team that are playing at a completely different level to us.
"But at the same time, I want us to be positive and if we get the chance to attack and play we have to be confident enough to do so.
The manager added: "In the Carabao Cup in August it was a tight game for 60 minutes, then their quality took over once they had caught us with a lightening quick counter from our corner.
"At the top level teams have the ability to hurt you by keeping possession or catching you on the break.
"We've got to stay in the game, it would be naïve to go there and go for the jugular straight away, but it wouldn't be the biggest shock in FA Cup history if we managed to get a result there."