Manchester United legend Rio Ferdinand has revealed Cristiano Ronaldo’s ego to be gargantuan.

The Real Madrid star was suffering from injury and has started training with his national squad in the past few days. Ferdinand, who played alongside the 29-year-old, while the two were at Old Trafford says the former United favourite used to read the majority of the articles comparing him with Barcelona forward Lionel Messi.

The former England international believes Ronaldo’s ego was the driving factor, which has seen him become the best player in the world.

“People see his ego – and don’t get me wrong, Cristiano’s ego is gargantuan! – but that is his fuel. It’s his inspiration,” Ferdinand wrote in his column in the Daily Mail.

“He reads all the articles written comparing him with Messi. ‘How can they say Messi is better than me’ he’ll ask. ‘I’ll prove that writer wrong.’ That’s his mindset. Driven.”

“Self-obsessed in the most positive way. Always looking to improve. That’s why he has become what he is, through effort and determination.”

“It didn’t all come naturally. He worked hard at technique and hitting the ball. He’s the hardest worker I’ve had the privilege to play alongside.”

“He’s a great team-mate, a companionable man, always involved in the changing room. But when it’s time to work he’s passionate about what he does and his emotion comes out,” he added.

Ronaldo has been exceptional for Real during the 2013-14 season and played a crucial role in helping his side win the Copa del Rey and the UEFA Champions League. The Portuguese star did not feature in the Spanish cup final and did not have much of an impact in the Europe’s elite club competition final against Atletico Madrid.

However, the United legend helped the Spanish capital club to reach the finals, who was brilliantly supported by Gareth Bale throughput the season. All eyes will be on Ronaldo during the 2014 FIFA World Cup as Portugal are one of the dark horses to win the summer tournament in Brazil.