A scan has revealed that Lucas Neill's knee injury is not serious and he could be back in action in two weeks.
Neill joined from Blackburn during the transfer window
The West Ham lasted only 32 minutes against Watford on Saturday and a scan revealed medial ligament damage.
But Hammers head physiotherapist Steve Allen said: "He has a grade one medial collateral ligament sprain - the least serious level of that injury.
"I wouldn't like to put a timescale on his recovery, but I am confident that he won't be sidelined for too long."
Neill will definitely miss the crucial game against Charlton on 24 February but could return for the home game against Tottenham on 4 March.
Neill's fellow new signing Matthew Upson is hopeful of playing against the Addicks.
Both Neill and Upson were injured on their debuts for Alan Curbishley's struggling side.
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