Sunderland fans may have found the sight of Jozy Altidore scoring two goals as the USA beat Nigeria in a World Cup warm-up game somewhat startling, but Arsène Wenger will not have been surprised.

Arsenal’s manager is famously “not a big fan of international football”. Indeed Wenger is downright sniffy about it. “When you think of international football, you think that it’s a level up,” he says. “But 99% it’s a level down. That’s why I prefer club football.”

Altidore seems to prove his point. After scoring only one Premier League goal in 30 appearances for Sunderland last season he has suddenly morphed into the defender-terrorising striker Jürgen Klinsmann, the USA coach, is pinning his hopes on in the “group of death” that also features Germany, Portugal and Ghana.

All the indications are that Gus Poyet suspects the Premier League is simply a field too far for a centre-forward that Roberto De Fanti, Sunderland’s former director of football, recruited from AZ Alkmaar for £6.5m last summer. Nonetheless, the Wearsiders’ manager will pray the joint forces of Klinsmann and Brazil unlock something in Altidore’s brain, somehow releasing a potential displayed in frustratingly rare flashes during the last domestic campaign.

Described as a poor man’s Emile Heskey, the 24-year-old is big, physically imposing and blessed with a ferocious right-foot shot, but has consistently failed to make his presence felt in opposing penalty areas.

Surprisingly lightweight when it comes to bullying rival defenders, not to mention holding the ball up, Altidore’s tendency to hesitate a moment too long or snatch at shots exacerbated a pronounced lack of confidence. He was too often dominated both on the ground and aerially, and struggled as a lone striker in Poyet’s possession-based 4-1-4-1 formation but got short shrift from the Uruguayan when he blamed his goal drought on Sunderland’s system and tactics.

Dropped for Sunderland’s Capital One Cup final defeat to Manchester City, sent to play for the Under-21s and largely excluded from Poyet’s starting X1 for the final two months of the season following Connor Wickham’s return from a loan stint at Leeds, Altidore looked anything but an international star. After months spent willing him to succeed, Sunderland fans nicknamed him “Dozy Anti-Score”.

He conspicuously failed to resemble the figure that scored 23 Eredivisie goals for AZ in 33 games during the 2012-13 campaign. Instead he reverted to the striker who flopped in La Liga after joining Villarreal for a record £4m-plus fee for an MLS import when he swapped New York Red Bulls for Spain. Loan stints at Hull and Turkey’s Bursaspor proved similarly underwhelming before that perhaps deceptively successful move to the Netherlands.

And yet Altidore is only 24 and theoretically has an awful lot going for him, particularly that ferocious shot. “Jozy’s had too much pressure,” Poyet said. “He came in with an idea he was playing for one manager [Paolo Di Canio] and the manager changed and we changed the system. You can see he’s got plenty of things to give but it’s about consistency – and scoring goals.”

Last August, many suspected Swansea had taken the bigger gamble in signing Wilfried Bony from Vitesse Arnhem for £12m but, after a prolific season, the Ivory Coast striker is possibly worth twice that. The difference is that, quite apart from using his own intimidating physique to impressive effect, Bony’s game is much more about guile, cunning, subtle skill and intuitive positional sense than Altidore’s.

“I think Jozy’s found it difficult for a mix of reasons including his position, how we play and the fact that it’s sometimes just how it goes,” said Poyet, well aware that his centre-forward is regularly likened to Afonso Alves, the Brazilian striker who struggled at Gareth Southgate’s Middlesbrough following a high-profile move from Dutch football. “You can just have runs when you’re roughly in the right areas but the ball won’t drop to you and I think Jozy’s suffered from a bit of that. You can make a run to the back post but the ball goes to the near post. It happens time and time again and then you get paranoid.”

Klinsmann seems to sympathise. “We believe Jozy is going to play a very big World Cup,” he said. “We think he will confirm our trust.”

If a nation’s hopes rest on Altidore’s reassuringly broad shoulders – along with Poyet’s plans possibly to seize the moment and sell him on during August’s prospective window of transfer opportunity – a charity in Haiti will be willing him to score in every game.

Despite his youth Altidore has established his own foundation to help underprivileged children around the world. The New Jersey-born, southern Florida-bred son of Haitian immigrants, he has concentrated his efforts on helping a country still devastated by the 2010 earthquake. Already he has raised considerable funds to support an orphanage and a major water well in Haiti.

Goals against Germany, Portugal and Ghana could not only transform a struggling forward’s career but change the entire futures of those for whom the work of the Jozy Altidore Foundation represents a lifeline.