During his first full season in charge the Croatian was magnificent in guiding the Hammers to a seventh-placed finish in the Premier League, as well as contending with the emotional farewell to Upton Park.
Then things started to unravel.
Player unrest accompanied problems settling into their new surroundings of the London Stadium and eventually fans support began to waver.
Bilić was granted time to overturn West Ham’s fortunes on three occasions last year but, despite only being in October, the 49-year-old is facing another ‘do-or-die’ week in charge of the Hammers.
Reports began to emanate after the disastrous 3-0 home thumping at the hands of Brighton & Hove Albion that the Croatian had just two more games to save his job. And, after their 4-1 defeat at home to Liverpool on Saturday, more questions will be asked.
But if the West Ham board do take the decision to part with their current manager, who would they look to bring in?
Football Whispers takes a look at the ideal candidates to take over at the London Stadium, should Bilić’s reign come to end.
We know the West Ham owners are an ambitious bunch when it comes to being linked with players in the transfer market, but could they tempt former Premier League title-winning manager Pellegrini to return to England?
The Chilean currently leads Chinese Super League side Hebei China Fortune but has been linked with both the vacancies at the London Stadium and Leicester City.
His no-nonsense style will certainly appease Hammers supporters and his success at Manchester City would breed new confidence into a struggling side.
But whether or not Pellegrini is attracted to a club languishing in the lower half of the Premier League table could cause complications.
Like Bilić, Rafa Benítez has never been short of a back-page lead during his tumultuous spells in England.
The impending takeover at Newcastle United could lead to the Spaniard’s exit, meaning the Hammers will be finely poised should they disperse with long-serving Bilic.
Benítez’s tactical prowess will endear himself to the West Ham faithful and his ability to get the best out of his players should stand the Londoners in good stead, as they aim to get out of their current predicament.
His knowledge of the Premier League is unquestionably an asset the Hammers would be desperate to maximise and given financial backing, Benítez can attract the sort of player fans have been crying out for.
Another former Premier League title-winning manager, the Italian is currently in charge of Russian giants Zenit Saint Petersburg.
However, all does not seem well for Mancini at Zenit and question marks over his future have surfaced in recent weeks.
The 52-year-old has spoken of his admiration for the Premier League in the past and an opportunity to return maybe too difficult to turn down.
West Ham have the financial support to offer Mancini a lucrative contract and if well-backed in the transfer market, the former Inter boss could be tempted to take the hot-seat at the struggling Hammers.
If West Ham turn to the assured presence of Sean Dyche, they won’t go too far wrong.
The 46-year-old has worked wonders with Burnley and has established the Clarets as a formidable force in the Premier League.
His feats at Turf Moor have been rightly recognised and Dyche has been linked with both vacancies at Leicester and Everton.
The Englishman has a habit of galvanising a group of struggling players, as seen when he took Burnley straight back up following relegation from the Premier League two years ago.
A name recently added to the list of potential successors, Nagelsmann has performed miracles with Hoffenheim in the Bundesliga.
The 30-year-old is seen as one of the hottest young coaching talents around after leading Hoffenheim into Germany’s top four last season, having taken over as the youngest manager in Bundesliga history.
His youthful exuberance will certainly rub off on a group of players bereft of confidence, but will West Ham opt for a manager with such little experience?