The Reds were in the running to land the Portuguese after he burst on the scene, but they Finally missed out to arch-rivals Manchester United
A highly-rated Portuguese forwards was generating loads of attention after exploding onto the scene in Sporting.
Several Premier League sides took the opportunity to cast an eye on Ronaldo’s possible, with Thompson sent on a scouting mission while working as assistant to Liverpool boss Gerard Houllier.
The Reds legend was amazed with what he saw, but was not able to commit to the financial package on the table.
As people back at Anfield weighed the merits of a move to get a then unproven adolescent, United seized the initiative and invested heavily in a guy who has gone on to claim five Ballons d’Or and cement standing as an all-time great.
Reflecting on what might have been, Thompson told The Athletic:”He was being touted around everybody.
“Tony Henry, the former Man City midfielder, was working for (representative ) Paul Stretford, who had been tasked with Jorge Mendes to drum up interest in England.
“They were desperate to get Ronaldo from Sporting and invited me over for a match. I was told the fee was 4 million but they explained that it could be paid over the duration of a four-year contract, so basically it was £1 million each year.
“I asked what type of salary he would want and they said it was £1 million per year after tax. That was a great deal for an 18-year-old kid, but they said that was negotiable.
“It was a Sunday and I explained to them that I had to return to Liverpool and talk to Gerard Houllier and see what we could do. I fed all of the information back to Gerard, who stated he would talk to [chief executive] Rick Parry.
“Lo and behold, the next week I am at Melwood when the yellow ticker on Sky Sports News says,’Manchester United signal Cristiano Ronaldo from Sporting for £12.2 million’ I could not believe my eyes.
Gerard asked me to call Tony to find out what had gone on. Tony explained that when he had got off the airplane on a Monday he’d got a call to say he had been off the offer.
He was clearly a large gift but no one could have predicted back then how good he was going to be.”
Thompson has also revealed that Liverpool were contemplating a move for Chelsea stalwart John Terry prior to the arrival of Roman Abramovich’s billions in Stamford Bridge scuppered these plans.
He added to the iconic Blues defender: “Chelsea were in financial trouble at the time and John had not signed a new contract.
I said he’d be ideal. John was only a young lad, but he was amazing. He was not blessed with amazing speed but he read the game so well and was clearly going to become a leading centre-half. The response was favourable.
“Gerard sent [manager of scouting] Alex Miller to receive his agent’s particulars and he came back in the players’ lounge with John’s phone number.
“Then a couple of weeks after Roman Abramovich bought Chelsea and they had all this cash. John and Frank Lampard both got large new contracts”