If Sam Allardyce sets his West Ham United team up in the same positive manner as he did when his club hammered Liverpool last Sunday, then the Irons can leave Old Trafford with a good result, asserts Paul Merson in his weekly prediction column for Sky Sports.
However, if West Ham attempt a safety-first approach then they may find themselves coming unstuck against the might of elite-level attackers like Angel di Maria, Wayne Rooney and Radamel Falcao.
Merson implies Allardyce must be inspired by MK Dons and Leicester City's ability to smash four and five past United, respectively, and with manager Louis van Gaal's admission that his side only have "one fit centre back available" (Marcos Rojo), there may be no better opportunity to bank points at the Theatre of Dreams.
"This game all depends on how Sam Allardyce approaches it," said Merson.
"If West Ham go to Old Trafford and have a go at them, like they did at home to Liverpool, then they will cause absolutely loads of problems because Man United are terrible at the back."
On top of United's well-documented defensive woes, are a number of omissions from their line-up as Chris Smalling (leg), Phil Jones (hamstring), Jonny Evans (ankle) and Tyler Blackett (suspension) are all unavailable for selection.
"If they go there, sit back and try to defend then they will fizzle out and lose, so surely you have to go there and go for them? I hope they do that because they’ll give them a right game.
"It could go one way or another and that’s why I’m making two predictions for this game," Merson concluded, before claiming the result could either be a score draw (2-2) should the Hammers get stuck in, or a home win (2-0) if West Ham are content to just sit back.