The French midfielder has arguably been one of the stars of the season this year, with a series of impressive displays for the Hammers so far.
Last weekend saw him at his scintillating best as he scored twice in the demolition of Blackburn Rovers in the FA Cup.
Those goals took him to nine in all competitions so far, making him the top goalscorer in Slaven Bilic’s side by some distance.
And unsurprisingly, Allardyce has singled him out as the man his side will have to keep their eye on when they travel to Upton Park this weekend.
"There's no doubt about it, he's been the outstanding difference because while he was injured, it was probably the worst run of results Slaven has had when he wasn't playing.”
"It shows what a difference one special player can make to your team."
While it would be easy to just single out Payet for special attention, that would be a dangerous move for the Black Cats to make.
He is not the only player to have impressed this season, with the likes of Manuel Lanzini, Victor Moses and Michail Antonio also having enjoyed strong campaigns.
Any of those three could be key men in the weekend’s game, and Allardyce would be foolish to tell his side to focus solely on Payet.