Tim Cahill has warned Everton that West Ham will want revenge after their midweek Carling Cup defeat.
Yakubu Ayegbeni struck a late winner at Upton Park on Wednesday to put Everton through to the Carling Cup semi-finals for the first time since 1988.
And Toffees midfielder Cahill expects West Ham to come roaring back when the sides meet at Upton Park again, this time in the Premier League, on Saturday.
"I can't emphasise how much we need to keep our feet on the floor," said Cahill.
"There is no way in hell that we will think that, just because we won on Wednesday night, we will win at the weekend because they are a good football club.
"The cup is a competition we want to do well in - and we are in the semi-final now. We enjoyed that the other night but now we have to concentrate on West Ham at the weekend, because they will come back firing.
"We are definitely wary there will be backlash but we have to prepare in the same way.
"It is a quick turnaround for us, and we have to make sure we are in the right shape to take on an in-form West Ham team on Saturday."
Cahill also had high praise for Nigeria forward Yakubu, who has now scored 10 goals in all competitions since joining Everton in the summer.
"He is very important for us," Cahill added. "He is a big boy, he holds the ball up, brings people into play and causes some trouble.
"You saw that at the end, where he got into West Ham's faces - and fortunately the ball fell to him. He is an opportunist.
"Yak's form is priceless, and his goal statistics speak for themselves."