EAST RUTHERFORD, N.J. -- Portugal winger Nani expects the United States to prove difficult opponents when the two sides meet in the Amazonian city of Manaus on June 22.
Germany and Portugal are the favourites to emerge from Group G, which also contains Ghana, but Nani fears Jurgen Klinsmann's side could cause problems.
"We expect a strong team with a good mentality," he said when asked about the U.S. after his side's 5-1 victory over Ireland. "They have a lot of confidence. We know that we have to do our best and prepare ourselves to play that game at the best that we can do."
Despite the gap between the two sides in the FIFA World Ranking -- Portugal are fourth while Klinsmann's men are 13th -- the favorites have experienced an upset at the hands of the U.S. before.
In 2002, the last time the two teams played each other at the World Cup, the U.S. claimed a 3-2 win over their heavily favoured opponents as they rallied to the quarterfinals of the tournament -- still the best-ever finish for the North American side. Portugal, meanwhile, failed to advance from the group that year.
The U.S. take on Ghana in their opening match on Monday, June 16, while Portugal face Germany.