Alan Knill says he still feels the magic of the FA Cup, as the Blades prepare to face National League outfit Barnet in the third round at Bramall Lane on Sunday.
And Chris Wilder's number two insists United will have to perform like they have done in the Sky Bet Championship to avoid what is a potential banana skin against the Bees.
He remarked: "For myself and probably Chris too, before we came here, we were that team, the underdog going to a big club believing you've got a chance.
"You can play with no fear, nobody expects much from you and at the end of it you can reflect and think you've played really well and got a result.
"We've got to be at our best. If we are it will be a tough game for Barnet, but all the time you must respect the opposition, irrelevant of the league they are from."
Knill added: "I got knocked out a lot as a player, but the FA Cup is a great competition. People say it has perhaps lost its magic, but not for me, you still have that opportunity to go a cause a shock.
"I've always enjoyed it as a player and manager, despite not having the best memories, playing the likes of Manchester City and Manchester United, that's really exciting."