The Hammers have recovered from a dreadful start to the season to record back-to-back clean sheets lifting them out of the bottom three in the process.
A 2-0 win over Huddersfield and hard fought 0-0 draw at West Bromwich Albion last time out have been something of a grind.
But those results have owed much to the return of Andy Carroll to the Hammers side.
His full-blooded style and aerial threat occupies defenders and invariably makes West Ham a more difficult proposition.
But when he was substituted with the game still in the balance against the Baggies Carroll made his feelings clear that he wasn't happy, shaking his head and taking his time to walk off as he was replaced by Diafra Sakho.
Many fans understood Carroll's frustration particularly given Sakho's much-publicised attempts to leave the club during the summer.
Others feel the striker needs to be handled carefully given his propensity to suffer injury with worrying regularity.
Now Bilic has warned the striker in an interview with the club's official website.
“He looked unhappy (to come off) but we have quality players on the bench and we changed the whole three up front," Bilic told whufc.com.
"We had Ayew, Arnautovic and Sakho, and I was very happy with the way they kept the shape, defended and pressed.
“We wanted to score a goal, which is why we put three quality players up front.”
Of course West Ham fans will want to see their players desperate to play for the club like Carroll.
But players must show professionalism too and conduct themselves in the right manner.
Bilic has been under intense pressure and the last thing he needed was Carroll making a big song and dance of his substitution.
Carroll should take a leaf out of Javier Hernandez's book as the Mexican has - for the moment at least - accepted being substituted in West Ham's matches of late despite playing out of position for the sake of the team.