Declan Rice will be out for around four weeks because of a knee injury, West Ham manager David Moyes has confirmed.
The midfielder, 22, suffered the problem while on international duty with England.
He played the full 90 minutes in both last week's wins over Albania and Poland, having sat out their opening World Cup qualifier against San Marino.
West Ham are in the chase for a Champions League place and Moyes said it was a big blow to lose Rice, who had been an ever-present this season.
“It’s disappointing. We knew after the England game he wasn’t going to be available. Anyway, we move on," Moyes told Sky Sports.
“We’ve been over the disappointment of that feeling and it gives other people opportunities and that’s what squads are for and, hopefully, we’ve got the squad to deal with it.
“We know we’re missing a good player but the team’s been playing really well.”
Alongside a picture of himself with his thumb up, Rice wrote on Twitter: “Rehab has started. Gutted to be missing the game (against Wolves) tonight.
"Overwhelmed by all the support but I’ll be back in no time. Come on the boys!”