Carroll made his first start in more than eight months in the 2-0 defeat to Watford on Saturday.
But his return to the Hammers' starting line-up was marred by an embarrassing mistake which gifted the Hornets the first goal.
Meanwhile, up the other end the big striker missed two gilt-edged chances to get his side back into the game.
Carroll has come in for criticism on social media since, despite getting the winner at Chelsea the week before.
And things have just got worse for the big Geordie after boss Bilic told the club's official website that he is not his number on striker.
That honour goes instead to Diafra Sakho, who missed the game at Vicarage Road with a thigh strain.
'We missed Sakho up front'
Sakho is a player Bilic believes is crucial to a successful West Ham side and one he is desperate to see fit again to face bogey team Everton this weekend.
"It cost us big time but we didn’t lose because of that," Bilic told whufc.com reflecting on Carroll's mistake in his own box which led to the opening goal.
“We missed Sakho up front and he was one of those players who has that kind of energy and he is the man who is pressing up front, although Andy was very brave.
"So he was missed and I hope he is going to be back for Everton.”
Unselfish Sakho has the legs to make Hammers tick; Carroll is the plan B
It may not come as much of a surprise to Hammers fans that Sakho is seen as the main man up front.
His tireless running, unselfishness and willingness to chase lost causes, harry defenders and close down the full-backs has been essential to the East Londoners and their terrific start to the season.
But can a club like West Ham seriously afford to have their record £18 million signing sat on the bench as a plan B?
That would seem Carroll's logical place at the moment given the impact he has made as a second half substitute in recent games against Norwich City, Crystal Palace and Chelsea where his contribution won the Hammers no less than seven points.
The former Liverpool striker may accept the super sub role for the time being while he continues to work his way back to full match fitness following his latest extended injury lay-off.
But it is highly unlikely he will be happy to sit on the Upton Park bench long-term and if Sakho stays fit it could give Bilic a problem to solve in the not too distant future.