The Hammers have completed what looks to be some very good business this summer already even if they are yet to gel on the pitch following the opening day thrashing at the hands of title hopefuls Manchester United.
Slaven Bilic has brought in experienced defender Pablo Zabaleta to solve his problem right back position, England goalkeeper Joe Hart, Marko Arnautovic, striker Javier Hernandez and young prospect Saed Haksabanovic.
But with a net spend of just £10 million so far, there is speculation the Hammers are far from done in the window.
The 25-year-old - who was a key figure in helping Portugal win the European Championships last summer - has been denied a move to the Premier League before now as Sporting have always proved notoriously difficult to negotiate with.
But West Ham are said to be confident of closing out a deal.
However, the club could face late competition from ambitious Marseille, according to reports in France.
The Ligue 1 side have already derailed Bilic's best laid plans once when they unsettled star player Dimitri Payet who ultimately forced through a cut price return to the club back in January.
And according to Foot01, the French side have registered a late interest in Carvalho while West Ham haggle over the fee.
Foot01 says Portuguese media claim contact has been made between Marseille and Sporting concerning Carvalho.
The report states that it is the player's preference to move to the Premier League but that Sporting are proving to be 'very greedy' which could well open the door for Marseille.
After the 4-0 humbling at Old Trafford there is no doubt West Ham desperately need a player of Carvalho's calibre.
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