At the start of the season Warnock told his newly-promoted side not to expect to get anything from matches against the Barclays Premiership top four of Manchester United, Chelsea, Arsenal or Liverpool.

In that respect the Blades have surpassed themselves as they beat the Gunners 1-0 at Bramall Lane in December, having drawn 1-1 at home with Liverpool on the opening day of the season after the visitors were awarded a debatable penalty.

No-one gives United a chance at Stamford Bridge - where Chelsea have not lost in the league since February 2004, a run that even pre-dates manager Jose Mourinho's arrival - but that is the way Warnock likes it.

"Sixty-odd games without losing a game at Stamford Bridge - who's going to think about little Sheffield United? I bet we are about 20-1 (to win)," said the Blades boss, whose side are seven points above the relegation zone.

"You put zero against all the top four. Any points against them home or away are bonuses. We have got three points off Arsenal and one off Liverpool and that is the difference of where we are (in the table) more or less.

"They are all on a lot more money than us, they are better players, more technically gifted than us but I think that epitomises all my life.

"I have always been up against it and that is when I think we should enjoy it."

Although he expects his side to play with more freedom because of the lack of expectation on them, Warnock still expects them to keep things tight.

The United manager was hugely disappointed with their last encounter against one of the 'big four' - a 4-0 defeat at Liverpool which included two penalties in the first 25 minutes.

"You don't want to get mullered and you are quite likely to get turned over by the likes of Chelsea, Arsenal, Manchester United and Liverpool," he added

"But at the same time I think there is a way of playing them - I didn't see much of that at Anfield but I hope to see it against Chelsea.

"It is when it is self-inflicted that annoys me."

From the apparent comfort of a 10-point lead over their relegation rivals a month ago, the Blades could see that cut to just four should results go against them.

And that should focus the players' minds sufficiently with six weeks of the season to go.

Warnock continued: "No disrespect to anyone but it is not going to be Chelsea and Man United away who decide whether we stay in the league.

"We have got seven other games to get the sufficient points but I think we have to go to Stamford Bridge and Old Trafford and be a bit more positive.

"Goal difference could be very important and that is why I was gutted we lost eight goals to Charlton (4-0 winners over West Ham on the same day) with the result against Liverpool.

"I hope we can defend better against Chelsea early doors than we did do at Anfield. I think we need to pass the ball more quickly, support more quickly and not forget what has got us where we are."

Despite a fortnight elapsing since their last match - the 1-1 home draw with Everton - defender Chris Lucketti (foot) and midfielder Mikele Leigertwood (ankle) have still not sufficiently recovered from their injuries.

However, midfielders Michael Tonge and Nick Montgomery both return after serving one-match suspensions against the Toffees.