The Hammers were joined by Manchester United and Arsenal in the stands.
The Portuguese midfielder has attracted interest from across Europe this summer after a series of impressive performances in midfield have caught the eye.
He has already been linked two of the big sides in the Premier League, with Manchester United having been continually been mentioned as suitors while Arsenal have also scouted him.
Indeed, according to the Guardian, the Red Devils recently moved one step closer to securing his signature as they discuss a potential £46m move for him.
They weren’t the only ones in attendance though, with the Red Devils represented, as well as Arsenal and La Liga giants Barcelona.
Whether Slaven Bilic’s side are serious contenders for his signature remains to be seen, although his rumoured price tag would price them out of the market.
The Hammers will likely have their attention elsewhere as they look to improve their forward line this summer instead.