Fair play. On.
There was loads of doubt about Ronaldo from all quarters just to add to what's being said in here, particularly throughout his second and third season. Rooney looked absolutely destined to be top drawer, but with Ronaldo this frankly ridiculous player just began to emerge from about February of 2006 onwards. There were signs of aerial ability, a goalscorer etc, but beyond excellent dribbling ability and technique he didn't excel many ways like he does now. It really took him a while to really start looking like a consistent goal threat, and in many ways it was unimaginable that he'd end up like the player he is today. He's completely different. Maybe during that closing period of 05/06 you would've been sensible betting on him becoming about 70-80% as good as he was the following year, but still as a more orthodox winger. Can't remember anyone seeing him having a season that would draw comparisons with Best, nor did anyone forecast the goalscoring machine that came on the scene from 07/08 onwards.
Basically:
Rooney/Fabregas/Messi were seen as dead certs.
Ronaldo was in a category below that - maybe in a category similar to Rafael whereby you could definitely see a world class player, but only on the basis that flaws were ironed out and strengths were made more consistent.
Worth noting that Fergie did say something like "in a few years, these two are all you'll ever be talking about" in regards to Rooney and Ronaldo. He definitely saw it coming, just as he did with Rafael when he said 'sometimes...you just know".