Much has been expected of Marko Arnautovic since his £20m move to the London Stadium in the summer. The Hammers have fielded many luxury imports over the years, blessed with talent, but not always associated with hard work. nor being a team player.
Some have flourished, and some have floundered, but fans had high hopes of discovering another Paolo Di Canio or Dimitri Payet type figure when Arnautovic signed in July.
Yet it hasn't all been plain sailing in the first few months of his Hammers career, with fans and pundits questioning Arnautovic's work rate and team ethic, raising questions over the longevity of his potential career in the East End.
Things got off to a rocky start, with the 28-year old struggling to make an impact under boss Slaven Bilic. Sent off in his second appearance at Southampton for violent conduct, the Austrian failed to break back into the team on a regular basis, often aimlessly wandering around in the appearances he did make.
Producing the kind of performances that can make fans turn on you in a heartbeat, Arnautovic was doing nothing to make any friends in the East End. Failing to track back, losing possession in key areas and showing a lack of desire to get stuck in just some of the many failings being attributed to the Austrian.
But all of those early season troubles suddenly evaporated with a sudden transformation in November. Enter, David Moyes.
Addressing several issues inherited from the Slaven Bilic regime, Moyes was quick to ambush his players in the first few press conferences that he gave.
Critical of players fitness levels and focus, Moyes vowed to change the ethos and culture currently surrounding the club. One thing he was quick to clarify. Passengers would not be carried, and every player would be expected to work harder and play for the shirt.
Many felt a number of those scathing comments were indirectly aimed at Arnautovic, with the Austrian engaging in a war of words with leading pundit Gary Neville just as Moyes took over.
An abysmal showing in the 3-0 home defeat to Brighton doing little to appease rising tensions at the club, with Arnautovic bearing the front of fans frustrations for an abject, and thoroughly effortless performance. The Austrian was quick to bite back though, showing for the first time that maybe he wasn't all about the money. Maybe he did care. And maybe he was about to start showing it on the pitch.
Fast forward seven weeks, and Arnautovic has begun to fulfil the potential of his hefty transfer fee and Hammers fans are singing his praises. Five goals in his last five league outings, all since December 9th, have seen the winger turn into West Ham's main goal threat.
Playing in a more central front with the freedom to roam across the pitch, the Austrian looks a lot more comfortable in a setup that combines strict disciplined defence with slick counter attacking football.
The team have reaped the rewards of Arnautovic's personal form also, earning wins against Chelsea and Stoke in recent weeks, and putting in improved performances against Arsenal and Bournemouth, the latter a game the Hammers should really have won.
His most impressive performance perhaps coming in the face of advertising to his old employers Stoke City. Mercilessly booed throughout the 90 minutes for comments made after his departure, Arnautovic ran the show at the bet365 stadium.
An enchanting pantomime villain performance was capped with the second goal in a resounding 3-0 success, testament to the new strength of character called for by Moyes on his arrival.
Now, without his presence, the Hammers seem toothless in attack and lacking any real penetration. Fellow big-money signing Javier Hernandez has thus far failed to fire this season, and with the Austrian having become the club's leading scorer in the space of two weeks, Arnautovic is likely to be bestowed with the unenviable task of being David Moyes' lead talisman.
It could however be a role that the maverick frontman continues to relish as he looks to establish a reputation of being West Ham's go to player. Bang in form at a time where his team have needed him, Arnautovic's form for the remainder of the season could well be the determining factor in West Ham's fight for survival come the end of the season.