Clarke accepts they go into the tie as rank outsiders.
He said, “We are under no illusions, and know we need to have to be ten out of ten on performances.
“The fans have done their bit getting behind the boys with the amount of tickets that have been sold, and we want to thank them for that by putting in a performance that does ourselves justice, and does the fans and the town proud.
“We’ve got to stand up and be brave, with or without the ball. That’s the standard you need to be on the level of world-class players playing in the Premier League.
“We want to win every game, and as someone new to the club, I wanted to start well, and the cup run has given us a platform to do that. We’ve got an important game at Burton too, and I have to make sure that decisions are made with an eye on Saturday too, so that the team is fresh enough to take on all challenges.”
He added, “It’s a really proud moment for me as a council estate kid from Mansfield leading out Barnsley at Old Trafford against a team I grew up following, but I want lots of proud moments in my time at Barnsley, and we want to make tomorrow night as magical for the fans as possible.”