The striker, a summer signing from Swansea City, picked up an injury on his first competitive match for the Hammers.
Chelsea's John Terry in action with West Ham United's Andre Ayew
The Hammers appeared to have solved their summer long search for a striker with the capture of Ayew from Swansea City in a £20 million deal ten days ago.
However, things quickly turned sour as the forward pulled up with a hamstring injury in his debut against Chelsea on Monday.
West Ham United's Andre Ayew receives medical attention before going off injured
The injury has proved to be a bad one, with it looking like he will be absent for the first four months of the season.
That leaves Bilic’s side in need of a striker once again, but Bilic has insisted they will not be forced into panic buying a replacement, although he does admit they are targeting another midfielder.
“Andre Ayew’s thigh injury is a big blow for us,” he told the London Evening Standard.
“[But] there will be no panic buying — maybe we are lacking one midfielder. Hopefully, we will qualify for the Europa League group stages but, even if we don’t, we need one more in that position.”
West Ham's Andy Carroll
While Bilic is hinting they will not be targeting another striker after Ayew’s injury that would be surprising to say the least.
With Diafra Sakho also out injured and Jonathan Calleri likely to be behind after starring in the Olympics, that leaves Andy Carroll as their first choice forward.
While he appears to have overcome his injury issues, that is not an ideal situation and it would actually not be that surprising to see another striker targeted.
West Ham manager Slaven Bilic before the game