Victory in the lunchtime clash would stretch United's advantage over Chelsea to 12 points, at least for the few hours before the champions take on Portsmouth at Fratton Park.

Even if Chelsea can win that match and avoid any slip-ups in their other game in hand, Jose Mourinho's squad would -- because of United's vastly superior goal difference -- still be left with the task of making up seven points on their rivals in the space of nine games.

On United's form this season that looks a tall order and it helps to explain why Mourinho was so frustrated to see Sir Alex Ferguson's side play well below par at Fulham last weekend and still emerge with a win, thanks to Cristiano Ronaldo's late solo strike.

"Completely undeserved," Mourinho complained with some justification. And his mood will not have been improved by indications that his hugely influential skipper, John Terry, could be forced to rest for several weeks after being knocked unconscious by a flying boot in the League Cup final win over Arsenal.

United's current lead was opened up while Terry was recovering from back surgery over the Christmas and New Year period and Mourinho will almost certainly have to rely once more on Michael Essien as a stand-in centreback at Portsmouth, at the expense of the Ghanaian's midfield drive.

United, in contrast, have enjoyed the luxury of a fully fit squad for most of the season while the increasing maturity of Ronaldo and Wayne Rooney has dovetailed nicely with the revitalised performances of the likes of Ryan Giggs and Paul Scholes.

Presuming he plays at Anfield, Giggs will become only the second United player, after Sir Bobby Charlton, to have made 700 appearances for the club.

Liverpool's own title hopes may have disappeared but they are unbeaten in 30 league matches at Anfield, where United were eliminated from last season's FA Cup on their last visit.

Pride is also at stake in what is arguably the most competitive derby clash in English football. "I think it's getting enhanced each year and the media make a big thing of it -- the players feel that, the fans feel that," said Ferdinand.

"Mentally it would be a massive advantage if we can get a win but we are not thinking about any team other than ourselves. If we can win it will be great, if we don't it's not the end of the world, but the three points are what we are looking for." Elsewhere, Arsenal badly need a good performance at home to Reading as they seek to get their season back on track after three straight defeats and the fallout from last weekend's League Cup final, which has resulted in Kolo Toure, Emmanuel Adebayor and Emmanuel Eboue all being banned.

At the bottom, Watford, who look doomed to relegation, could destroy Charlton's chances of beating the drop when the two sides meet at Vicarage Road.

After knocking four goals past fellow strugglers West Ham last weekend, Charlton are within six points of Wigan, the club currently occupying the last survival spot.

Wigan are away to Manchester City on Saturday, a match that might test the watching FIFA President Sepp Blatter's enthusiasm for English football, while West Ham entertain Spurs hoping to avoid a sixth consecutive defeat.

Fixtures
(1500 GMT kick-off unless stated)
Saturday
Arsenal v Reading, Fulham v Aston Villa, Liverpool v Manchester Utd, Manchester City v Wigan Athletic, Newcastle v Middlesbrough, Portsmouth v Chelsea (1715), Sheffield Utd v Everton, Watford v Charlton

Sunday
Bolton v Blackburn (1335), West Ham v Tottenham (1600)