STANFORD -- One of the major keys to U.S. hopes in the World Cup will be which version of Jozy Altidore shows up in Brazil next month. At the moment, no one is sure.

Will it be the electric 24-year-old striker who scored in a record five straight national team matches last year and drilled eight goals overall in 14 appearances, playing a starring role in the team's qualification?

Or will it be the Altidore who languished through a nightmare season with Sunderland in the Barclays English Premier League this year, scoring just two goals in 31 matches, being one of the league leaders in fouls, and ultimately spending as much time on the bench as the pitch.

Altidore set his jaw at the team's Stanford training site Thursday when asked if the horrific Sunderland experience had somehow derailed his confidence and game.

"I'm the same guy I was before," he said tersely. Asked later if he was worried that there would be any carry-over effect from his English flop, he was just as short, declaring, "I'm not concerned."

That certainly won't stop outside scrutiny of a player who has become noted for remarkable extremes in performance. In 2012-13, playing for AZ Alkmaar in the Dutch league, Altidore scored 31 goals in 41 matches, a record total for an American player in Europe. It was one reason Sunderland paid a hefty fee to sign him to a four-year contract.

His play in the Netherlands certainly had a carry-over effect to his national team play, too, so it's only natural to wonder if there might be a downside effect from the Sunderland experience. U.S. coach Jurgen Klinsmann hasn't seemed very concerned that Altidore is somehow scarred, noting last month that the New Jersey native is a virtual lock for the squad.

But what happened in Sunderland? While it's true that Altidore didn't live up to expectations, the entire team was pretty terrible. The club endured a midseason coaching change and played at or near the bottom of the EPL much of the year until a late-season rally saved the team from relegation. Altidore said it wasn't until late that the team started to take on a more focused and aggressive offensive approach like he was accustomed to at Alkmaar.

He also maintained he is not the worse for having gone through such a rough experience.

"You're going to go through tough times," he said. "A career in soccer, a lot of it is mental, man, and you have to stay strong and tough mentally. There are going to be good moments, too. I feel fine and I'm excited, and I'm ready to get going."

Altidore said the wealth of scoring talent the U.S. possesses as well as Klinsmann's penchant for implementing different formations with his front line have him primed for the three weeks of training camp. He insisted he shouldn't be the undue focus of the Americans' scoring potential.

"We have guys in abundance who can get the job done," Altidore said. "The most important thing we have to get ready for is to get through the group, because we're going to be playing teams with a lot of talent."

Altidore believes the allure of playing in the World Cup will bring out the best in his game, and that the Sunderland experience will not be a drawback.

"I definitely think now, when you come to the World Cup and the season's behind you, it matters what you do now going forward," he added. "Just believe the reasons why you're there, how you got there, and keep training. Sometimes it just goes like that, there's just no other way to put it. You just have to keep training hard, and understand that it's going to get better, and it will."

  • Four more players arrived in camp -- forward Clint Dempsey, defender Matt Besler and midfielders Michael Bradley and Graham Zusi -- bringing the total number of players at Stanford to 25. Goalkeepers Tim Howard and Brad Gazan, forward Aaron Johansson, midfielder Jermaine Jones and defender Geoff Cameron have not yet reported.

    Follow Carl Steward on Twitter at twitter.com/stewardsfolly.