(CNN) -- American striker Clint Dempsey says the U.S. team has drawn confidence from impressive performances against Brazil, Spain and England but says Friday's World Cup clash with Slovenia is a match his side cannot afford to lose.
Dempsey struck the lucky shot which slipped through England goalkeeper Robert Green's hands to earn a 1-1 draw for the U.S. in its opening game of the World Cup last Saturday in South Africa.
But the Americans played well to avoid defeat against one of the World Cup's most highly fancied teams and Dempsey said the experience of reaching last year's Confederations Cup final had given the American players the confidence to compete with the competition's best sides.
The U.S. team beat European champions Spain 2-0 in the semifinals of that tournament and led Brazil by two goals in the final before going down 3-2 to a late winner.
"Before the game (against England), we knew that if we played our best, we would get a result out of the game and we did that at the Confederations Cup playing against the top teams," Dempsey told CNN.
Midfielder Michael Bradley also said the U.S. team had become "battle hardened."
"We've had three or four years of playing against the best teams in the world. We've gotten to the point where when we've stepped onto the field against a team like England, there's a sense of we've been here before," Bradley told CNN.
"We know what the game is going to be like and we know what we need to do to be successful. That mentality is going to take us where we want to go."
With the top two in the group advancing to the knockout stages, the U.S. and England are favorites to progress ahead of Slovenia and Algeria.
But with Slovenia beating Algeria in their opening game, Dempsey said the U.S. could not afford to slip up against a team representing the smallest country to qualify for the finals.
"If we lose this game, potentially we'll be out of the tournament, so we have to go out there and make sure that, yeah, we do take chances going forward but calculated risks," said Dempsey. "You can't just say 'everybody go because we've got to post a win' and be countered and get scored on."
Bradley, the son of U.S. coach Bob Bradley, said the American players would treat Slovenia with the same respect they showed England.
"The term favorites or underdogs... these words, you guys use them but they're not words that we use," Bradley said.
"We had a lot of respect for England, we knew it was going to be a difficult game, and I can tell you we have a lot of respect for Slovenia and we know that will be a difficult game too."