Tottenham Hotspur can draw level on points with fourth-placed Chelsea if they beat West Ham United at White Hart Lane on Saturday.
Tottenham are fifth on the English Premier League table and three points behind the defending champions, who occupy the final Champions League qualification place.
If Spurs beat West Ham they will move on to 51 points, but would remain fifth due to an inferior goal difference.
Nevertheless, a Spurs win would put the pressure back on Chelsea ahead of their home match against third-placed Manchester City on Sunday.
But the visitors to White Hart Lane will be desperate to foil Tottenham and collect vital points in their battle to escape relegation.
West Ham are third from bottom, level on points with Birmingham in 17th place and just one point behind Blackburn Rovers in 14th.
If they win and other results go their way, Avram Grant’s side could leapfrog a number of the teams above them and leave the drop zone behind.
They bowed out of the FA Cup at the quarter-final stage with a 2-1 defeat away to Stoke City on Sunday, but had previously been unbeaten after four matches in all competitions – including a 3-1 win over Liverpool.
Spurs’ last hitout was a hard-fought 0-0 draw at home to AC Milan last Wednesday, with the result securing their passage to the quarter-finals of the Champions League following a 1-0 away win in the first leg in Italy.
Despite their impressive achievement in European competition, Harry Redknapp’s side are without a win in their last two league outings.
They lost 3-1 away to Blackpool on February 22, followed by a 3-3 draw away to Wolverhampton Wanderers on March 6.
West Ham have only long-term absentees Junior Stanislas and Jack Collison on the sidelines.
Tottenham will be missing centre-backs William Gallas and Jonathan Woodgate, while fellow defenders Vedran Corluka, Ledley King and Younis Kaboul are also in doubt.
Midfielders Wilson Palacios and Tom Huddlestone are unavailable through their own injury problems, while Rafael van der Vaart could also miss out.