That, as their coach, Stuart Raper, will be telling them this week, would be a serious error because Sheffield have it in them to emulate Castleford as one of this year's big improvers. "The only good thing about the draw is that we're at home," said Raper. "I'll be taking the same approach that I did for the last two rounds and I'll make sure that the players do, too. It's my job to keep their feet on the ground."
That is a job which will come naturally, because Raper knows enough about the Eagles to regard them as a real threat.
"John Kear is one of the best British coaches and they have strengthened well," he says. And the main newcomer at Sheffield is a player whose qualities Raper knows at first hand.
"David Watson was at Cronulla when I was starting out coaching in the lower grades there and I know what he can do if he is given a chance."
What Watson might do given the chance has been a worry for a series of clubs, however brilliantly he might perform on the field. He has left a trail of misdemeanours through a career in three countries, including a failed drugs test for cannabis and another sample that he neglected to provide.
There is no doubt about the ability of the New Zealand international, however. When Kear succeeded in signing him this winter, he said that he was so excited that he could not sleep.
Watson has given some of his previous coaches sleepless nights for other reasons, although it was one of them, Peter Fox, who recommended him to Kear, with a promise that his wild days were behind him. It seemed a good risk to Kear, who was convinced that a stand-off capable of doing the unexpected was precisely what his well-structured team needed.
"He's been as good as gold," says Kear. "He's punctual, reliable, hard- working and he's obviously enjoying himself. He's doing everything I'm asking of him in defence and he's adding that 'X-factor' in attack."
As a Castlefordian, born at 33 Wheldon Road, just down the street from the ground, Kear has watched his home-town club's rapid progress under Raper with pleasure and admiration. "I think they've done an absolutely marvellous job there; not just Stuart, but the marketing people they've brought in. There's always a Castleford player on TV or a Castleford player in the papers."
Saturday will also be Sheffield's day in the spotlight - the first time they have ever appeared on terrestrial television.
"It's an important moment in the history of this club and we're looking forward to it and the profile it can give us," Kear said. He will be unable to play his latest signing, the prop Steve Molloy - who is cup-tied - but the ease with which Watson and his other recent recruit, Michael Jackson, have settled in gives him confidence that they can halt his local club's bandwagon.
"They are a very good side at the moment. They would command respect from Wigan or anybody, but then so would we."