“It can only get delayed or, dare I say it, possibly even cancelled if there’s a pitch invasion.
“There are security issues and we want this all to go smoothly and as planned.”
West Ham could still finish in a Europa League spot if they beat United to dent their chances of claiming a Champions League place.
Hammers boss Slaven Bilic said: “It’s a big game because it’s the last at Upton Park.
“But it’s massive because we also want to secure a European spot.
“Yes, the players will be emotional – and there is nothing wrong with that – but we have to win.”