Demerit joined Watford from non-League Northwood
United States defender Jay DeMerit says Wayne Rooney must be nullified if his side are to win their opening World Cup Group C match with England on Saturday.
The 30-year-old, who is being released by Watford, is in contention to start.
Demerit told BBC Radio 5 live: "You have to fear guys like Rooney because of their calibre.
"But do you let him take advantage of that? Of course not. You go in as prepared as you can be and then make his day as difficult as possible."
DeMerit has played all of his professional football in England and is now looking to get one over on the nation where he has plied his trade since 2004.
He added: "If we won it would be an upset. Obviously we go in knowing who they are and knowing how world class they are.
In order to beat an English side, as good as they are, you need to find as many advantages as you can
"For us it's a matter of doing our best to shut them down and making sure we do the right things on the day."
England captain Rio Ferdinand has been ruled out of the tournament because of injury and DeMerit, who has 18 international caps, said the US will try to capitalise on the 31-year-old's absence.
"It's not like they don't have the quality of players that can fill in for him," he stated.
"But when new guys come in maybe they haven't had a chance to gel like the rest have.
"In order to beat an English side, as good as they are, you need to find as many advantages as you can."
The US overcame Australia 3-1 in their last pre-tournament friendly on Saturday.
An Edson Buddle brace and Herculez Gomez strike were enough for victory, despite Everton's Tim Cahill scoring for the Socceroos.
Demerit will look for a new club after the competition, with Watford deciding not to renew his contract, along with full-back Jon Harley and forward Will Hoskins.