Bilic plans to make changes for the EFL Cup clash, with summer signings Sofiane Feghouli and Edimilson Fernandes among those set for a chance to start.
But the Croatian has made it clear he is desperate for the Hammers to get through to the semi-final stage.
“We are going to do everything we can to beat them,” he said. “Man United are probably also going to change their team.
“What we expect is the same shape from them, same kind of football, just different names.
“When we say we are going to give a few players a chance it doesn’t mean we are going just to play a game, and that we regret beating Chelsea in the last round.
“It’s a quarter-final, which means if you win you are in semis and that’s a big thing, and only a couple of games to final.”
The sides drew 1-1 at Old Trafford in the Premier League on Sunday.
Javi Gracia said it was always going to be an uphill battle for Watford after conceding so early against Liverpool on Saturday.
Schalke 04 boss Dominico Tedesco paid tribute to goalkeeper Ralf Fahrmann after his 76th-minute penalty save proved crucial in a 1-0 win over Wolfsburg.
Mattia De Sciglio stunned that Juventus were shocked to be held to a goalless draw with SPAL on Saturday.
Sunderland have suspended midfielder Darron Gibson with immediate effect after he was charged with drink driving.
Jose Mourinho's recent bad frame of mind was still present despite Manchester United beating Brighton 2-0 at Old Trafford on Saturday, a result that puts them into the last four of the FA Cup.
Mohamed Salah continued his astounding goalscoring form on Saturday, hitting four goals as Liverpool thrashed Watford 5-0 at Anfield.