Sheffield United: Chris Wilder challenges his players to prove a point during Friday's Steel City showdown

Wilder issued the challenge following the 1-0 defeat at Nottingham Forest, which saw the visitors surrender first place in the Championship table.

Although the 51-year-old admitted he was disappointed by both their performance and result against Aitor Karanka's side, it was United's inability to master the art of taking points from games they fail to dominate which caused him most concern as the countdown to this week's eagerly anticipated showdown begins in earnest.

"I honestly can't remember the last time we won or drew a game when we weren't at full tilt," Wilder insisted. "Maybe I should take that as a compliment of sorts because we're still in the picture and so it shows we are getting the absolute maximum from the players.

"But also, when we're not at our best, do we become just an average team? It's certainly something we're going to have to get better at if we want to maintain a challenge and I guess we'll find out."

United were far from their fluent best at the City Ground although, in truth, Forest also struggled to fulfil their potential until Grabban scored his 10th goal in 11 outings from João Carvalho's cross. 

With the two players signed for nearly £20m during the close season, Wilder admitted it served as a reminder that lapses in concentration can prove costly as his squad steps up in class.

"Against better players, that's what happens," he continued. "They punish you if you switch off for just a moment.

"We'll sit down and come up with the answer but honestly, for the life of me, I don't know the last time we didn't get a point that we'd 100 per cent earned. I don't think, during my time here, that I've stood here and said 'We've been absolutely battered there but we've won.' Obviously I want us to play well all the time but it would be nice, if you get my drift, if from time to time I could say that."

The search for answers could see Wilder make changes for the meeting with Wednesday at Bramall Lane on Friday night as Kieron Freeman was replaced by George Baldock during the closing stages of the trip to the Midlands and Mark Duffy hopes to recover from injury. Chris Basham is also expected to return following suspension. "We've got another huge game coming-up now," Wilder said. "So we've got to learn and make sure we get better at doing these things.  Because, even though we've come a long way in a short space of time, we don't want to be just an average team. I don't think I'm being too critical, I want us to be at our best."