West Ham United star Scott Parker broke down in training and is now having a course of injections in a frantic bid to patch him up for the relegation-threatened club's crunch game against Blackburn at Upton Park on Saturday.
It was thought that Parker was certain to have recovered from his Achilles injury in time and had been earmarked for a return against Steve Kean's struggling Rovers side - a match that the Premier League's bottom club dare not lose.
But a Hammers source told ESPNsoccernet: "Scott Parker broke down in training yesterday [Tuesday]. He has had injections which have a 50% chance of working."
The recently named Footballer of the Year has missed West Ham's last three games.
Hammers boss Avram Grant is convinced his side can pick up the seven points he thinks they need to stay up and end a run of five straight defeats starting against Rovers, but that target is going to be deeply compromised if Parker is not able to play.
Parker's injury is believed to have been aggravated while playing for England where he made his mark under Fabio Capello. But because he returned to the Hammers and played on for a while, the east London club have been thwarted in their bid to claim compensation from the FA.
A Hammers insider added: "He played a few games injured, but couldn't play anymore. The injury is not major, but he's in acute pain with his Achilles and really needs a break. He's played 38 games for West Ham this season, plus games for England."
Meanwhile, with Matthew Upson (dead leg) and James Tomkins (knee) injury doubts for the remainder of the season, right-back Jordan Spence has been recalled from a loan spell at Bristol City.