Manuel Pellegrini has quickly put his stamp on his new team with six additions already to his squad.
Former Arsenal star Jack Wilshere has been the highest profile signing so far as the England international joined his boyhood club on a free transfer.
They have also signed Andriy Yarmolenko (£17.5m, Borussia Dortmund), Ryan Fredericks (free), Lukasz Fabianski (£7m, Swansea) and Issa Diop (£22m rising to £25m, Toulouse) this summer.
But where would attacking midfielder Felipe Anderson slot into their team?
At the moment West Ham rely heavily on Manuel Lanzini to create their chances. But his form has dipped since Dimitri Payet left the club for Marseille.
They also have players like Marko Arnautovic, Michail Antonio, and Yarmolenko to rely upon to create chances.
But Anderson gives them a player capable of creating out of nothing, something they have lacked since Payet left the club.
West Ham could try to play in a similar way to Liverpool, with a few attacking options together rather than play with an out-and-out striker.
The creativity they would have with Jack Wilshere, Mark Noble, Lanzini, Arnautovic, Antonio, and Yarmolenko would be frightening and they would be the envy of most Premier League sides.
Last season he netted eight goals and assisted ten others. He is a keen dribbler and made just under four successful dribbles in every game he played. When it came to key passes, he offered normally a couple every game, underlining his creativity for the team.
If the Hammers can pull off this transfer, then they will be getting one of the best creative players in the Premier League.
Is he worth £35 million?
West Ham have already spent just shy of £50 million this summer and if they do spend the £35 million on Anderson, then it will represent their biggest ever transfer window spend.
That being said, the money being spent is in line with other top sides in the country and West Ham needs to be pushing towards the top six of the Premier League.
At £35 million Anderson would represent a huge outlay on a player who has no prior Premier League experience and very little international experience.
Last season he was not a regular starter at Lazio, yet he was able to contribute quite significantly - 17 of his 32 appearances were as a substitute.
Yes, he has quality. That much is clear from his time at Lazio. But can West Ham afford to spend a huge chunk of their budget on a player who is reasonably unproven?
The reward though far outweighs the risk. If they can get Anderson playing at the levels he did for Lazio this past season, then they will have one of the Premier League’s most impressive attacking midfielders.
What do you make of West Ham's business so far? Let us know in the comments below.