Sam Wallace: Nani seizes centre stage after flailing in the wings

The winger's display at Arsenal suggests that the shy boy from the wrong side of Lisbon's tracks is emerging from Ronaldo's shadow

Nani served full notice of his great potential against Arsenal last Sunday (GETTY IMAGES)

Sir Alex Ferguson described Luis Nani as "a shy boy" when he summed up the personality of the winger who finally stepped out of the shadows on Sunday in the victory over Arsenal. And for anyone who seeks to follow Cristiano Ronaldo at Manchester United, shyness is just not an option.

It has taken Nani two and a half seasons at United to produce a definitive performance against a big team, although that alone – as well as the decent games he has had against Hull and Manchester City – does not dictate that he is destined to become one of United's untouchables. For the first time since he joined, however, that £17.3m transfer fee, including add-ons, looks like a safe investment.

It is too easy to say that Nani lived in the shadow of his compatriot Ronaldo who was already an established star when the former arrived in 2007, but without him there are now no excuses for not stepping up into the first team. He also does not have to live with being perceived as the sidekick any longer.

There is a tradition at United that the academy players perform a comedy show at Christmas in which they are allowed to poke fun at the senior team – a challenge they take quite seriously. It was reported that this season the "actor" playing Nani held a picture of the departed Ronaldo and cried. The year before Ronaldo was depicted walking Nani on a dog lead.

In terms of playing in the first team, Nani had the most to gain from Ronaldo's departure. He could also point to Ronaldo's occasionally indifferent form in his first three seasons at United – although Ronaldo was much younger than Nani when he joined. It is Antonio Valencia's arrival that has had the biggest impact on Nani; the Ecuadorian has started 18 league games, twice as many as Nani

While Nani has also suffered from injuries this season, he has surged ahead of Anderson, the Brazilian midfielder who joined from Porto in the same summer. It was Anderson who made the bigger impact at the start, although both were extra-time substitutes in the 2008 Champions League final.

That United were prepared to send Anderson out on loan this month suggests now that his relationship with Ferguson is strained. As for Nani, Ferguson's assistant Mike Phelan's comment after the Arsenal game that "the penny has dropped" hinted at the frustrations that Ferguson and his coaches have had with a player who has tended to drift in and out of games in the past.

Ferguson indicated that Nani had struggled to adapt at first. "Maturity is one thing," he said. "He's 23 now. He's a very shy boy. There's no question about that. Maybe his personality's getting stronger and better to deal with playing for us every week. [The Arsenal game] was an example of that maturity."

While Ronaldo has developed beyond all expectations, there are still similarities between him and the Portuguese winger who was left behind when United's most famous player departed for Real Madrid last summer. For a start, both Nani and Ronaldo were kids from poor families who were regarded as outsiders in Lisbon. Ronaldo was from the island of Madeira and mocked in the Portuguese capital for his yokel accent; Nani's family moved from the former Portuguese colony of Cape Verde, the islands off the west coast of Africa, when he was a child. His father stayed there and it is his older brother Jose Almeida who has been a de facto parent in his absence.

Jose is now a licensed Fifa agent representing his brother and working closely with Jorge Mendes, arguably the most powerful agent in world football. The brothers grew up in the fairly notorious Lisbon suburb of Massama, home to the capital's poorest immigrant populations.

While Ronaldo grew up in the poor but idyllic town of Funchal, Nani really did come from the wrong side of the tracks. He was recruited by Sporting Lisbon to play in their academy when he was 12, 18 months younger than Ronaldo. His mother moved to the Netherlands during those years but Nani stayed in Portugal to try to make a career in football.

Despite his background, he does not revel in ghetto gangster-chic. He does not get through the same volume of glamorous girlfriends as Ronaldo – Nani is still with his long-term girlfriend – although he was named as present in one infamous tabloid story about Ronaldo that was subsequently immortalised in song at Old Trafford. There is no suggestion that he did anything untoward.

In the past Nani has shown flashes of what United saw in him when they picked him up from Sporting Lisbon, especially the goals against Tottenham (August 2007), Middlesbrough (October 2007) and Liverpool (March 2008) but he has never been able to deliver it consistently. That has been a problem for him in international football, where Carlos Queiroz picks him in Portugal squads but prefers Simao Sabrosa when it comes to picking the team.

Last summer, Nani spent his free time in Portugal playing in a charity beach sports tournament to raise money for a foundation run by the Porto defender Bruno Alves. He seems more relaxed in his home country, which is where in November he committed what is deemed a cardinal sin at United by giving an honest, no-holds-barred insight into life at the club.

Among other things, Nani wondered at Ferguson's ability to "compliment you one minute and attack you the next". But if anyone has embodied that kind of unpredictability at Old Trafford it has been Nani, although he has a wonderful chance to establish himself now.

The new Ronaldo? Not quite yet...

* Nani's improved form has evoked comparisons with former Old Trafford winger Cristiano Ronaldo. The 23-year-old's record, however, pales against Ronaldo's at the same stage of his United career.

* Nani has scored 12 goals in 89 games for the club, two years and seven months after joining from Sporting Lisbon in 2007. Ronaldo hit 20 in 121 games by the same stage of his United career, including scoring in an FA Cup final. He was named Young Player of the Year and also included in Uefa's team of the year.

James Mariner