The 18-year-old winger was a sought-after prospect at the time, with a long queue of illustrious suitors chasing his signature.
He eventually chose a move to Old Trafford after dazzling Alex Ferguson's side during a pre-season friendly, but the now-Juventus star revealed that things could have gone much differently.
"There had been contacts with so many other teams," Ronaldo told TV1, as reported by the Manchester Evening News.
"Valencia, for example, were one of them. I met with Arsene Wenger and was about to go to Arsenal. I talked to Barcelona, Real Madrid and Inter too.
"But after the friendly against Manchester United, who were already interested, they became even more interested and they sped up negotiations and signed me."
Ronaldo went on to win three Premier League titles and the Champions League with the Red Devils, before joining Real Madrid for a then-world record fee of £80 million in 2009.
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