Manuel Lanzini has warned Liverpool that he and his West Ham United team-mates are ready to cause an upset at Anfield on Saturday evening.
David Moyes' men come into the game in fifth place in the Premier League and a shock victory would boost their hopes for a Champions League finish.
But second-placed Liverpool will be favourites after winning their last six league matches as they attempt to pile more pressure on leaders Manchester City.
The Reds can close the gap to City to just three points with a victory over the Hammers.
But Lanzini, speaking to West Ham's official website, said: “We know Liverpool is one of the best teams in the world at this moment, but I think we are confident in our form and our team and we are all focussed on this.
“Of course, we have a team to play well in these kinds of games, but need to focus on our game."
West Ham were knocked out the FA Cup in their last outing while Liverpool were able to progress to the quarter-finals of the competition.