West Ham’s Andre Ayew could be out until Christmas as a result of the thigh injury sustained in Monday’s Premier League match at Chelsea.
The club’s record signing lasted just 35 minutes of his debut at Stamford Bridge before limping off.
The Hammers have not given a time frame for Ayew’s absence, saying last night that he is facing “a significant rehabilitation period”.
However, Jack Sullivan, the son of West Ham’s joint chairman David Sullivan, earlier wrote on Twitter: “We are devastated that Ayew will be out for about 4 months. He needs surgery.”
The news will be a major blow for manager Slaven Bilic, who had spent all summer attempting to bolster his attack before finally landing Ayew last week.
He is already without another new signing, Sofiane Feghouli, through injury for the Europa League play-off first leg against Astra Giurgiu, while Aaron Cresswell and Manuel Lanzini are also sidelined.
In addition to the Hammers’ injuries, new left-back Arthur Masuaku is cup-tied, while the influential Dimitri Payet did not travel.
Meanwhile, Darren Randolph insists he is comfortable being the club’s cup competition goalkeeper.
First choice Adrian may have been unavailable for the clash anyway, having yet to train since he was on the wrong end of Diego Costa’s controversial late tackle at Chelsea.
But Bilic usually picks Randolph for the cup competitions, so the 29-year-old is understandably desperate to get to the group stages.
The Republic of Ireland international said: “I don’t mind it, we had a good cup run last year and I ended up playing a few games.
“Hopefully this year it will be the same. It’s down to me to perform whenever I get the chance to play.
“I feel good, I feel confident and I’m enjoying my football and being involved with everything happening with West Ham at the moment.
“It’s a great experience to play against teams from other countries and travel places, it’s only going to benefit the team.”
West Ham reached Europe last season via the Fair Play League, but were knocked out in the qualifying rounds by the same opposition they face this year.
Randolph admits the mood in the squad is different this time around having reached the competition by virtue of their performances.
“Any chance you get to be in cup competitions like this you have to relish, it’s where everybody wants to be,” he added.
“I think it feels better because of how we performed last year, that it was down to us and how we played that got us here.”