What we know and don't know about West Ham's transfer window so far: Summerville exit and Gustavo Sa pursuit

West Ham United are in the process of reshaping their squad for the Championship.

The Hammers suffered the ignominy of being relegated from the Premier League last season.

That has already resulted in Mateus Fernandes leaving for Tottenham Hotspur in an £85million deal.

Others could follow the Portugal midfielder out of the exit door before the close of the transfer window, too.

Nuno Espirito Santo will hope for more bodies in the door before they face Portsmouth in the EFL Cup first round on 8 August, and then the trip to Burnley for their Championship opener eight days later.

Here's what we know and what we don't know about West Ham's transfer window so far.

What we know: Gustavo Sa closes on West Ham move

The Hammers have yet to bring any new signings through the door at Rush Green, although youngster Keiber Lamadrid has seen his loan move made permanent.

However, there have been plenty of players linked and the hope is that incomings will be announced soon.

Among the first of those could be Portuguese 21-year-old attacking midfielder Gustavo Sa.

Portuguese A Bola has reported that the Famalicao ace is closing in on a £17million move to London Stadium.

The fina details are being ironed out, but everything appears to be pointing towards Sa becoming a Hammer in the coming days.

What we know: Nuno Espirito Santo has a clear priority

Having decided to stick around to oversee West Ham's attempt to get straight back up, Nuno will want reinforcements across the board.

But it is clear that the Hammers are looking a little light of options in defence, particularly at centre-back.

Axel Disasi has completed his loan spell and returned to Chelsea, while Jean-Clair Todibo has an uneasy relationship with Nuno and will likely depart.

Max Kilman and Konstantinos Mavropanos remain on the books, though the latter could attract interest, while Soungoutou Magassa could go there but is more at home in defensive midfield.

What we don't know: Will Crysencio Summerville stay?

It feels inevitable that more players will leave before the close of the window.

Crysencio Summerville is a player whose future looks hugely uncertain, amid links to Manchester United.

That is likely dependent on whether the Red Devils opt to sell Marcus Rashford this summer, a sale that is not certain to happen.

But with links to the likes of Paris Saint-Germain, Aston Villa, Tottenham, and Fulham, there is no shortage of interest in Summerville.

He impressed for Netherlands at the World Cup, despite their last-32 exit, and that is surely only going to increase interest in his services.

What we don't know: Can West Ham convince Jarrod Bowen to stay?

One of the million dollar questions this summer is whether captain Jarrod Bowen will remain at the London Stadium.

The 29-year-old did not get selected for England's World Cup squad and may have concerns over his long-term Three Lions future.

But Bowen has also hinted he would like to stay and lead the fight for promotion next season.

The difficulty is, Bowen is sure to have plenty of admirers, and former Hammers boss David Moyes has been linked with taking him to Everton.

Aston Villa are also said to be keeping tabs on Bowen, though any incomings at Villa Park may depend on player sales.