The Eagles are currently fourth in the npower Championship but must put their promotion bid on hold on Tuesday night when they head to the Britannia Stadium after their initial third-round tie ended goalless.
Boss Ian Holloway may opt to rest some of his key players but Australian midfielder Jedinak insists they can still spring a surprise.
The Eagles won at Manchester United in the League Cup last season and the same outcome would secure a fourth-round visit from Manchester City at the end of the month.
"Would we like an extra game? Probably not, but we've got it and we've just got to deal with it," said Jedinak.
"It's not frustrating. We are professional athletes so we just have to get on with it, whether the manager decides to go with you or not, we are all in it as a group and it's got to be done.
"I don't see why we can't go through. There's a lot of confidence around the place and we are playing with that confidence.
"Every game is difficult and you have to treat the opposition with respect. But in saying that you can't stray away from what you believe in and your philosophy of football.
"We know it will be a difficult game, they have got a great record at home in the Premier League so we are not going to kid ourselves."
Kagisho Dikgacoi is on international duty with South Africa, while fellow midfielder Owen Garvan has a knee injury. Wilfried Zaha is expected to play amid continued speculation he is heading for the Premier League this month with Manchester United and Arsenal reportedly lining up bids.