Why Man United and David Moyes Face Dilemma over Nani

Expectations for Portuguese wingers signed from Sporting Lisbon are high at Manchester United.

One arrived at Old Trafford in 2003, with blonde highlights and a few spots, and left six years later as the world's most expensive player. 

In the intervening years he won the Premier League three times, the Champions League once and was crowned the best player in the world. Not to mention inheriting David Beckham's No. 7 shirt and making it his own. 

Cristiano Ronaldo is a tough act to follow. But it's been especially hard for Nani, who made the same move from Lisbon to Manchester.

Early in his United career, Ronaldo developed a talent for frustrating United fans. There were only so many step-overs they could take before demanding an end product. To his credit, it was something Ronaldo developed.

He become stronger, quicker and more direct. The loose passes were replaced with stunning goals, the aimless crosses with inventive assists. Frustration became adulation. 

But after six years, the same spell Ronaldo had at Old Trafford is still infuriating United fans with Nani. In fact, there are few players who infuriate them more.

Anderson? Perhaps. Jonny Evans? Maybe in the past but certainly not any more. 

What frustrates them more than anything is that his ability isn't in question. Quick and two-footed, he's got all the attributes needed to be a star.

But he's not. 

His highlight reel is packed with spectacular goals, step-overs and eye-catching celebrations but he can never claim to have been a regular starter.

The parallels with Ronaldo are obvious. 

Two Portuguese wingers signed from Sporting Lisbon for big fees. Both arrived in England with blistering pace and frightening natural talent, but raw and rough around the edges.

But Ronaldo was transformed from exciting prospect into the best player in the world and left for a world record £80 million. 

The stories linking Nani with a move away this summer quote rather more modest figures.

Ronaldo's departure for Real Madrid in 2009 was billed as a watershed moment for Nani. Finally out of the shadow of his international team mate, he would begin on the same meteoric rise.

But it hasn't happened. 

Even last season, as Antonio Valencia and Ashley Young struggled to find their top form, Nani couldn't hold down a regular place in the first team.

Sir Alex Ferguson ditched his wingers all together in some games—United won impressively at Newcastle in October with a midfield of Michael Carrick, Tom Cleverley, Shinji Kagawa and Danny Welbeck.

Nani's season might have ended differently had he not been harshly sent off against Real Madrid at Old Trafford. 

He was a surprise choice, especially with Wayne Rooney left on the bench, but he looked to be taking his chance before Cuneyt Cakir flashed his red card.

His luck hadn't changed by the time Chelsea came to Old Trafford for an FA Cup tie later that week and he was forced off with an injury.

After two goals in a preseason friendly against Crewe this week, Nani will hope for another chance to impress under a new manager. 

But time is running out if he's going to hit the heights expected of Iberian wingers.

Rob Dawson is Bleacher Report's lead Manchester United correspondent and will be following the club from a Manchester base throughout the 2013-14 season. Follow him on Twitter here @RobDawsonMEN