Manchester United host Chelsea at Old Trafford on Sunday in what amounts to a playoff for the English Premier League title.
United top the table by three points from second-placed Chelsea, with the same goal difference as the defending champions.
A draw will preserve their advantage going into the final two matches of the season, while a win will see Sir Alex Ferguson’s team take a six-point lead and virtually wrap up the title.
But if Chelsea can produce a repeat of their victory at Old Trafford late last season, Carlo Ancelotti’s side will draw level with United on points and go top on goal difference.
It would be a remarkable comeback for a team who found themselves 12 points off the pace earlier in the season after their worst run in more than 10 years of top-flight football.
United are expected to field a much-changed line-up from the 11 who defeated Schalke 4-1 in the Champions League semi-final second leg on Wednesday.
Key men Rio Ferdinand and Nemanja Vidic are likely to return to the centre of defence with midfielders Michael Carrick and Ryan Giggs also expected to come back in.
Fullback Patrice Evra picked up a knock after coming off the bench in midweek, while striker Wayne Rooney did not train before the Schalke match because of a tight hamstring.
But Ferguson has confirmed that both will be fit to start against Chelsea.
“Patrice got a kick,” Ferguson told MUTV.
“I was ready to substitute him but he said he was OK. Wayne will be all right. I wasn’t prepared to take a risk.”
While wingers Antonio Valencia and Nani both started against Schalke, it is likely only one will be retained to provide a creative outlet in Sunday’s match.
Goalkeeper Edwin van der Sar is almost certain to retain his place.
Chelsea have enjoyed a week off since beating Tottenham Hotspur 2-1 at home on Saturday.
Didier Drogba and Fernando Torres started the match at Stamford Bridge.
But Ancelotti may be forced to sacrifice one of the centre-forwards if he is to shore-up a midfield that was outfought in the Champions League quarter-final defeat at Old Trafford on April 12.
Remarkably for this late stage of the season, both sides are largely free of injury concerns.
Chelsea have a full squad of players to choose from, with only long-term absentee Owen Hargreaves sidelined for United.