It was Portugal’s first training session after the humbling defeat against Germany and Nani showed up with a star and his squad number shaved into his hair. It was as if he had not quite grasped that this was the time to knuckle down rather than show off a new haircut.

A fresh crop does not necessarily mean a player will fail to work hard, of course – the newly shorn Luka Modric has showed plenty of application at this World Cup – but it does, perhaps, hint at a player’s priorities and, more importantly, it reinforces the feeling that Nani sometimes is more about style than substance. There is no doubt that the Manchester United midfielder is outrageously talented. He has everything you expect from a world-class footballer: quick feet, mesmerising technique and stamina. But it never quite comes together for him.

It is not for a lack of ambition, that is for sure. In 2011 he told Público: “I want to be one of the best in the world, I want to be on the top and I hope to get there as soon as possible. It will need some patience, I know. If I can get there in one year, perfect. But, if it takes two or three years, it’s also good.”

Those three years have gone now and, with Cristiano Ronaldo struggling with a knee injury, Portugal desperately need Nani to fulfil his promise and step up in their crucial Group G tie against USA on Sunday. At the moment he is somewhere between good and great but the problem is that he has been somewhere between good and great ever since he joined Manchester United from Sporting CP – and that was seven years ago.

Increasingly, observers are asking where is the progress? In Nani’s defence he has suffered from injuries this season but expectations of what he can produce for the national team has dropped so low that there was even a debate in Portugal whether the 27-year-old should be included in Bento’s 23-man squad before the tournament. A large portion of fans – especially from the north – wanted the 30-year-old Ricardo Quaresma to take his place.

In January, Quaresma returned from a spell in UAE and finished the season with nine goals in 24 matches. In 2014, Nani played only three incomplete matches for United.

Bento, who coached Nani at Sporting, stood by his former player and left Quaresma at home, reportedly for his lack of commitment to the national team at Euro 2012 when the winger remained an unused substitute. “Nani has different characteristics from Quaresma,” Bento said at the time. “Quaresma did not compete for a period and after two months in Porto everyone said that he could be in the national team. Why can’t the same happen to Nani now? I think these 23 players are the ones that serve in the best interests of the national team.”

Portugal’s coach has stood by his everlasting plan, positioning Ronaldo and Nani on the wings, alongside Silvestre Varela, Vieirinha and the young Rafa Silva, players with low-profiles and willing to wait for a chance to shine.

Nani stepped up to the challenge. In the final warm-up match, a heartening victory over a fragile Republic of Ireland, the winger set up a brilliant goal, only to see it disallowed for offside.

That is what the Portuguese expect from Nani, the would-be king from Cape Verde. The magic is there for everyone to see, just waiting to be unleashed, but it just does not happen often enough. Portuguese fans and experts know that Nani always tries his hardest for the national team and there is an acceptance that he is doing his best in what is, apart from Ronaldo, not the best generation of talent the country has ever seen.

He had a good Euro 2012 but then his form fell away in an erratic qualification campaign for the World Cup when Portugal lost to Russia and failed to beat Northern Ireland at home. Nani sustained an injury and missed matches against Israel (3-3) and Azerbaijan away (0-2). Bento instead opted for Varela and then Vieirinha, who himself was later injured. In October 2013, the winger finally found his scoring touch, netting the second against Luxembourg in a 3-0 win but he has failed to score in a competitive match for the national team since November of 2011. That is almost two years, which is too long for a player who wants to conquer the world.

United seem to think that he will fulfil his promise one day and he recently signed a contract until 2018, causing some eyebrows to be raised in Portugal. There were reports that Juventus were interested in signing Nani but United did not want him to go on the cheap – or run his contract down and leave on a free.

Luís Boa Morte, a Portuguese who played in the Premier League for West Ham and Fulham, summed up his countrymen’s feelings when he said: “As we all know, Nani is an excellent player. I just wish he has a season at his highest level and without injuries.” He is still, for all the injuries, one of the best players Portugal have but he remains a postponed star, a long-lasting promise of brilliance. He missed the last World Cup in the most ridiculous of fashions, injuring himself doing a backflip while celebrating a goal. At least he made it to Brazil and, with Ronaldo struggling, Portugal need him more than ever.