Chris Wilder's key Sheffield United demand as he sends warning to players ahead of Luton Town clash

Chris Wilder has warned his Sheffield United players that they could be substituted "after 10 or 15 minutes" if they don't show the courage and bravery to get on the ball and impact games for the rest of the season. All eyes will be on United's character this week after their 5-0 drubbing at the hands of Aston Villa appeared to hammer another nail into their relegation coffin.

The tests don't get any easier, either, with a trip to the febrile atmosphere guaranteed at Luton Town's Kenilworth Road next up this weekend. As Wilder said after the Villa hammering, many of United's players have experienced the praise and adulation in the good times and must now accept the other side of the coin when they come up short so dramatically.

What will be interesting is how they bounce back this weekend. Many of this squad have been written off before and defied the odds; those who were signed during Wilder's first spell in charge will have been brought to Bramall Lane with a big emphasis placed on their character and personality. It is, Wilder conceded, easier to play when the sun is shining and things are going your way. When you're up against it, you learn what people are really made of.

"For the position we’re in, to their credit, I'm seeing that they’re all accepting their roles and responsibilities," Wilder said recently. "They're all trying to get on the ball and trying to create. They are trying to risk as well, which you have to do. I've seen it in teams that are struggling and don't want to step into a game and then you're playing with 10 and then with nine. People find the skinny angles but I think they know from my point of view and from the supporters' point of view, that is unacceptable."

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But exactly how important is that bravery, in Wilder's book? "I've got to say it's possibly the most important characteristic that I would look at in a player," he revealed. "If I felt someone was hiding and not prepared to get on the ball and get through a game, I'd drag them off. Even if it was after 10 or 15 minutes. It means that much to me.

"As a professional footballer, you get paid well. When the sun's shining and you're top of the league and everything's fabulous, it is easier to play in that kind of environment. And when it isn't going as well and the pressure's on, and you're having a tough time individually, and the team's not rolling as well as it should be, it is a tough place. But you have to stand up and you have to accept that challenge and take it on board, and deal with it.

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"We've had enough times here when we've enjoyed the good times with our supporters. You accept that applause and that pat on the back, as a player. You accept the good things that get said about you, and you have to accept the other bit. When it isn't going as well, you might get cricitism for your performance. All of us, me included. And you have to take that on board. 

"If a game doesn't go well you have to go and front that up. You're willing to accept the praise but not the criticism? Come on. This is what it's about. You've got to take both things, and hopefully have more of one than the other. And that's something that you can affect. You can't affect it if you're hiding and you're finding those skinny angles. The game's hard enough, in whatever division. As soon as you start losing players and you're down to 10 and down to nine, then it becomes virtually impossible.

"And that isn't just letting yourself down. It's letting a lot of other people down. The player next to you. Your coaches, your manager. And most importantly, the supporters."