Manchester United's match against Arsenal on Sunday could still be hugely influential in the outcome of the Premier League title race if Chelsea maintains its recent good form this weekend.
If the Blues beat Tottenham at Stamford Bridge on Saturday, the defending champions will be just three points behind United by the time the league leader plays at Emirates Stadium.
Tottenham is fighting for Champions League qualification and also needs the points, so Chelsea is far from certain to be in a position to put that pressure back on United.
"We have to do our job and that's to win against Tottenham," Chelsea coach Carlo Ancelotti said. "It will not be easy because Tottenham are a very strong team but we have to keep it open in the Premier League until the last minute."
Ancelotti has a full squad to choose from, with Michael Essien fit following a knee injury and Ramires recovered from a hamstring problem that ruled him out of the last three matches - all of which Chelsea has won by scoring three goals.
Central defender Alex is also fit again following three games on the sidelines with a similar injury.
Chelsea is six points behind United with four games remaining and still has to play United, which is aiming for a record 19th English championship.
Tottenham is four points behind Manchester City, which occupies fourth place and the last of the Champions League qualifying berths.
"Tottenham are involved in a fight for fourth place and they will try to do everything against us because they have a chance to close the gap with Manchester City," Ancelotti said. "Maybe they will use this game to improve their season."
Spurs reached the Champions League quarterfinals in its debut season in the competition, but its chances of a second-straight top-four finish have been hit by consecutive draws against Arsenal and West Bromwich Albion.
"If we lose to Chelsea, and City win their next two games, it will be virtually impossible," Tottenham midfielder Tom Huddlestone said. "We have still got games to play though, so as long as it's possible then we won't give up."
Spurs have lost just one of their past seven meetings with Chelsea but have not won at Stamford Bridge since 1990.
"Two months ago, everyone was looking at these matches as league deciders - and they probably are," United manager Alex Ferguson said. "But we are going into them in good form so why can we not win them?
"Teams are going to drop points on the run-in, including Chelsea."
United, which has won the last four games of its seven-match unbeaten streak against Arsenal, can call upon Dimitar Berbatov, who returns after three games out with a groin injury.
"Hopefully we get to a point where we need to win our last home game - against Blackpool - to win the league," Ferguson said. "I would take that."
Also Sunday, Liverpool hosts Newcastle, Manchester City hosts West Ham, and Birmingham hosts Wolverhampton Wanderers.
On Saturday, Blackburn hosts Bolton, Blackpool hosts Stoke, Sunderland hosts Fulham, West Brom hosts Aston Villa, and Wigan hosts Everton.