Even without facing him on the pitch, anyone who watched Ronaldo play has a sense of how terrifying he must have been as an opponent.

The Brazilian looked superhuman compared to every other footballer of his generation.

His blistering speed, deft skill and ruthless finishing made him arguably the most complete striker the sport has ever seen.

There’s a common theme among those who have played against Ronaldo: the experience was simultaneously unbearable and captivating.

Mikael Silvestre enjoyed this strange ‘pleasure’ as a teammate of his at Inter Milan.

Describing Ronaldo in the latest instalment of Manchester United’s ‘Unscripted’ series, the 42-year-old wrote: “Now that guy was special.”

Arriving from Rennes, Silvestre expected to be tested by the Nerazzurri squad - but he was simply in awe of their then No. 9.

“The best way to learn is by practicing against these guys every single day. But facing Ronaldo in training… wow. That’s all I can say.

“You almost want to just stand back and watch him.

“Every day he’s inventing dribbles and moves, going in positions that you wouldn’t believe anybody could do, but he does it. It’s so natural and simple to him.

“What’s amazing is the speed of his movement. His speed with the ball and without the ball is something I’d never faced before and never did again.

“I was fast, which is fine, but normally when you are against a striker and he’s got the ball, with your speed you normally think you can get there, but with Ronny, he was always quicker and faster, even with the ball.

“When it comes to the games themselves, you’re glad to have him on your side. When you play a match with Ronaldo on your side, you feel like you’re playing 12 against 11.

“With him fit, nine times out of 10 you’re going to win the game. That’s your feeling before the game has even started.

Silvestre left Inter at the end of the 1998-99 season to join Manchester United, but it wasn’t the last he saw of Ronaldo.

The Red Devils met Real Madrid in the 2003 Champions League quarter-finals, and having marked Ronaldo before, Silvestre said: “I knew that you had to avoid diving in, especially with Ronny.

“Whichever way he wants to send you, he’ll send you. His sharpness, change of direction, all of it was just the top level.

“Ronny could get something out of his bag at any moment. That’s what makes him so special because most strikers have two or three moves that they are completely excellent at, but Ronaldo had 10, maybe 15.

“His best attribute was his ability to strike in a short space of time. Especially at the World Cup in 2002, he scored goals that were toe pokes.

“You knew that physically he was a bit diminished, but he’s finding the angle and his quick feet on the ground makes him shoot before you can even make a move.

“That’s where, for me, he was superior to every other striker.”

What a player.

Lionel Messi and Cristiano Ronaldo might produce the numbers, but no one will ever frighten defenders like Il Fenomeno did.