Ronaldo was signed by English Premier League giants Manchester United in the same year after impressing in a friendly against the Red Devils who had a preparation tour in Portugal.

"I was in Madrid by 2003 and I knew that Real scouts were watching Ronaldo," Martins told S on Thursday.

"I don't know why they didn't contract him," he added.

Recently, Ronaldo has expressed his interest to move to Spanish Liga as he is topping both Real Madrid and Barcelona's wish-list.

Ronaldo is having his best season at Old Trafford scoring 15 league goals so far to help Man United lead the table six points ahead of defending champions Chelsea.