Declan Rice has vowed to be “back in no time" after starting rehab on his knee injury.
Rice has played every minute of the Premier League season until now but has been sidelined for the start of West Ham’s run-in, starting against Wolves on Monday night.
Rice posted on Twitter: "Rehab has started. Gutted to be missing the game tonight.
"Overwhelmed by all the support but I’ll be back in no time. Come on the boys!"
The injury to Rice is a blow for West Ham but the Hammers are hopeful the 22-year-old will play again this season.
Without Rice, Mark Noble made only his fifth Premier League start of the season against Wolves.
Moyes is thin on options in central midfield and Noble, 33, is the obvious replacement despite his lack of gametime this season.
Noble, who has announced that next season will be his last at the club, has done well in the FA Cup this term but looked off the pace in the Premier League and cannot offer the same presence or energy as Rice.