Returning stars
Fabian Balbuena and Arthur Masuaku have been back in training since Tuesday after their time off following respective international exploits over the summer.
Neither played a whole load of game time for Paraguay at the Copa America and DR Congo at AFCON respectively, Masuaku only played 90 minutes and Balbuena double that, but both came through unscathed and were handed the mandatory 21-day break in the aftermath.
Angelo Ogbonna has failed to impress in the absence of Balbuena at centre back alongside Issa Diop and Winston Reid, while Masuaku is under pressure for his place from teenager Ben Johnson, who has outperformed Aaron Cresswell in pre-season.
Balbuena and Masuaku will both be rusty of course and are nearly a month behind their first team counterparts in terms of training and fitness so getting more than 45 minutes each on Saturday is unlikely.
But the pair are set to feature against Manchester City in the Premier League opener from the off so they will need to get up to speed quickly so Pellegrini has no issues in potentially leaving them out.
First glimpse at the new boys
We've seen David Martin and Roberto feature for the Hammers already in pre-season but now its time for the big-money duo to make their debuts - Sebastien Haller and Pablo Fornals.
West Ham have shelled out £65m on the duo and, like Balbuena and Masuaku, have been training at Rush Green since Tuesday. Haller is already ahead of Fornals as he had been in pre-season training with former club Eintracht Frankfurt while the Spaniard had a break following his Euro U21 Championship winning exploits.
Haller is the striker West Ham have been crying out for this summer aer ditching three of them from the squad of last season, while Fornals was a quick recruit from Villarreal this summer to bring even more attacking flair to Pellegrini's team.
They will be given time to settle of course but with the pre-season campaign already at its halfway stage, time is still of the essence. It's a first chance to see how the potential Fornals/Manuel Lanzini midfield axis can work, while Haller will be looking to the delivery of Felipe Anderson and Fornals' ability to split a defence.
It'll be a bit all over the shop to start with but that's what pre-season is for.
A new formation?
So far in pre-season we have seen Pellegrini stck to his usual 4-2-3-1 formation throughout the three games but with Fornals now in the equation, could that change?
The Spaniard's role in the team is more suited to a 4-1-4-1 formation, one that leaves Declan Rice horrendously exposed in defensive midfield so when Fulham attack, we could well see it revert back to the norm.
Going forward though, there is an abundance of attacking talent with Fornals likely to occupy a spot on the right and Anderson on the left with Haller or Chicharito through the middle depending on who is on the pitch.
Tactical flexibility is one of Pellegrini's strong points as a manager (he has many more) but he hasn't been able to show it yet in east London due to the terrible injury issues he had throughout 2018/19 to contend with.
