Shrewsbury boss Micky Mellon says it is vital his players maintain their focus if they are to knock Manchester United out of the FA Cup.
The Shrews host United for the first time in their history in Monday's fifth-round clash.
Louis van Gaal is under increasing pressure and defeat to the Sky Bet League One side will turn up the heat on the Dutchman even further.
Shrewsbury lost 2-1 to Chelsea in last season's League Cup after giving them a scare and Mellon knows how they can trouble United.
He said: "If I said we are going to go toe-to-toe with Manchester United, match them right up, hit possession in the final third and pin them right back, they'll think I'm bananas.
"We have to be realistic and say in every game you have a chance, we have to work hard on making that chance bigger.
"We did it against Chelsea, in certain areas of the pitch we knew we had to be good, certain personnel we had to stop service to, we also knew certain times in the game we had to get through, first 20 minutes, half-time, then we knew our chance had increased."
Shrewsbury only lost to Chelsea last season after a late Jermaine Grandison own goal and Mellon wants his side to approach the United game in the same fearless way.
He said: "I think we said, 'Let's acknowledge the fact that it's a huge game, a fantastic opportunity for us, a lot of people are interested to speak to us and see what we do, let's embrace that and enjoy it but really keep that focus on there being a game at the end of it'.
"Of course it's a huge game. But I've said to the players that I'm determined they're going to enjoy it because it's Manchester United and it's fantastic to be able to say that.
"So we'll try and enjoy it but keep that level of focus on it as well because we did that last time with Chelsea and it seemed to work really well."