The Hammers will face Premier League rivals United away from home at Old Trafford in the quarter-finals of the FA Cup on Sunday evening.
“We’ve got an FA Cup quarter-final to look forward to this weekend at Manchester United and I am backing the boys to go there and win, such is my belief in what they can achieve this season,” Lock wrote on West Ham’s official website.
“What I am saying is that, while we might not be favourites to go to Old Trafford and win, if you have the belief and talent in your squad then you can do it,” added the Englishman.
West Ham are in a great run of form at the moment, and will fancy their chances of winning against United at Old Trafford.
Manager Bilic is likely to field his best available lineup, and that is going to pose a massive threat to Louis van Gaal’s side.
United will also want to maintain their chances of winning the FA Cup, and playing at home will give them an advantage.
The Red Devils have not been playing well this season, but in a cup tie, the players will be determined to step up their game.