West Ham are sweating over the fitness of Jesse Lingard ahead of next week's trip to Burnley as the midfielder is reportedly struggling to overcome persistent leg problems.
The 28-year-old has been an inspirational mid-season addition to the Hammers squad with nine goals and four assists in his 11 Premier League matches for David Moyes' side so far.
The Hammers already have a significant injury list with key players Declan Rice, Michail Antonio and Aaron Cresswell on the treatment table in a crucial part of the season.
And according to The Sun, the Hammers could be without star man Lingard for Monday night's clash is still struggling with leg problems that nearly ruled him out of last week's London derby with Chelsea.
Lingard underwent strong treatment on his legs to make sure he was fit for the London Stadium clash, which Moyes' side lost 1-0 thanks to Timo Werner's first-half winner.
The on-loan midfielder from Manchester United pulled up with a leg problem during the match but the Hammers boss insisted the problem was cramp-related.
The defeat to Chelsea means West Ham lie three points behind the fourth-placed Blues with just five Premier League matches to play.
Thomas Tuchel's side could extend that lead to six points before the Hammers take to the field on Monday night, with Chelsea facing relegation-threatened Fulham in a west London derby on Saturday night.
Fifth-placed would secure the Hammers Europa League football, but Moyes' men are under pressure from three Premier League rivals - Liverpool, Tottenham and Everton behind them.
West Ham are one and two points ahead of the Reds and Spurs respectively, while Everton can move level on points with the Hammers should Carlo Ancelotti's side win their game in hand against Aston Villa.
Moyes is full of confidence that his Hammers side can achieve Champions League football despite back-to-back losses to Newcastle and Chelsea in recent weeks.
'We're in a decent position,' the Scot told Sky Sports after the Chelsea game. 'We have games to play, hopefully we're right in the mix for some sort of European football. I will push to make that the Champions League.'