Rovers have just two points from their last 18 in the league and Appleton said that the chance of a Wembley semi-final should motivate his players back to form.
"I think this is an opportunity to put the league to bed for a few days," he told the club's official website. "We've got a great opportunity to go and play at Wembley, it has been a while since the football club did that.
"So I'm sure the players will grasp that, they've got an opportunity to do something special.
"It is a quarter-final cup tie, two Championship teams going head-to-head knowing that the likelihood is that the winners will play one of the big boys at a magnificent stadium."
Blackburn have slipped to 13th in recent weeks.