Back in 1996 the Brazilian, 19, was on the verge of breaking out among the world's football elite.
Two seasons in the Netherlands had yielded an amazing 54 goals in 57 games and the teenager was also on the way to establishing himself in the Brazil national team, having picked up a World Cup medal at just 17.
One man paying close attention was Sir Bobby Robson, a legend of the game in England and at that time Barcelona's head coach.
"He was still only 19 but I told Barcelona we must have him, that we would be buying not only a wonderful player, but a player for the future," he was quoted as saying in the book Barca: A People's Passion.
"And he was much more than an alternative to our other front men: he was rare, different and exhilarating. He has different skills from other centre-forwards.
"He's an incredible dribbler; he dribbles like George Best, Tom Finney and Chris Waddle. He has an an amazing ability to just plough his way through."
Curiously, though, Barca and Ronaldo's future could have been much different had Robson landed his original target.
"I won’t lie, I was tempted to buy English players and very nearly bought Alan Shearer at Barcelona," he later told Four Four Two.
"We needed a centre-forward and the chairman asked if I knew one. I told him: 'I know a cracker, he’s English and he’s top'. It was just after Euro 96 and I approached Ray Harford at Blackburn. Ray told me he wasn’t for sale, and could I not disturb him by letting the press know of our interest.
"I told him he could trust me, and a week later Alan was sold to Newcastle! We got Ronaldo instead."
While the Catalans certainly did not lack the financial muscle to land Ronaldo following the failure to sign Shearer, reaching the young striker proved rather more difficult.
Enter Joan Gaspart, Josep Nunez's No. 2 at Camp Nou and later president in his own right. The official came up with a novel way to break the ring of steel around Barca's transfer target and convince him into a move.
"I even had to disguise myself to seal his signature," Gaspart revealed to Goal.
"It didn’t take long to reach agreement with PSV. The fee back then was 1,500,000,000 pesetas - around €15 million in today’s money.
"But the agreement had a little problem: we needed to get the player’s agreement and we needed it before July 15, because that was when the pact with PSV was set to expire."
When PSV got cold feet, however, Gaspart had to take drastic measures to keep the move alive.
"PSV realised they didn’t want to lose the player and they called the CBF in order to stop Ronaldo signing for Barca,” added Gaspart, who had no knowledge of the sudden change of heart upon travelling to Brazil to seal the deal.
"There were two security guards that didn’t want me to go through and see Ronaldo or any other player. I met a Spanish waiter in the hotel and he lent me his work clothes, gave me a tray and a Coca-Cola.
"I put on the disguise, said 'hello' to the security guards and told them a guest had asked for a soft drink. This time they let me past.
"I knocked on Ronaldo’s door and he himself opened it. He signed the contract right there, on the bed."
Ronaldo went on to spend just one season at Camp Nou, but he lit up Camp Nou with an impressive 47 goals in 49 appearances.
And to think that might never have happened if the great Robson had been more persistent in pursuing Shearer – or Gaspart less determined to bring the Brazilian to the Blaugrana.