Lionel Messi was absolutely unplayable in the 2011 Champions League final.
The Argentine scored his side's second and was brilliant throughout as Barcelona beat Manchester United 3-1.
Rio Ferdinand did all he could to stop Messi that day but was unable to do so.
11 years on from the final, Ferdinand has broken down the game in a tactical analysis video.
Posted on his YouTube channel, the Englishman speaks for several minutes about how Messi was able to dominate his side.
It makes for a fascinating watch and you can view it below... (Ferdinand speaks about Messi from 10:28 - 18:45)
Sir Alex Ferguson has previously said that the outcome would have been different had Ji-Sung Park man-marked Messi during the the game. It was an idea Ferdinand disagreed with.
Asked about Ferguson's claims, Ferdinand said: "If we said he were going to man-mark him... this guy Messi is an alien! He was already being allusive for us two [Vidic and myself]. So we were basically playing with two-men down at this point.
"If you man-mark him with Park, he's going to stand over here [the right-wing away from the game]. Now we're three men down! They've got bodies everywhere in here [the middle].
"I don't think even man-marking Messi in this game would have helped us. We weren't a pressing team by nature. The best teams in this era, we had to fight with. We were the best at transitioning when we won the ball and would turn defence into attack very quickly.
Football - Manchester United v FC Barcelona 2011 UEFA Champions League Final - Wembley Stadium, London, England - 10/11 - 28/5/11
Barcelona's Lionel Messi (R) in action with Manchester United's Rio Ferdinand
Mandatory Credit: Action Images / John Sibley
Livepic
"When you've got a team like this... man-marking Messi... he would happily stand there [the right-wing] and say 'come with me'.
"All of a sudden the game would develop, [Andres] Iniesta would get the ball behind our midfield and all of a sudden bang [Messi runs into the striker position]. There will be a few times where Messi will be the wrong side of Park and then it's curtains."
He continued: "There was two players that I played against and I've gone 'there's levels to this.' The Brazilian Ronaldo and Messi. He took your best attributes away with the way he played. Because he's playing away from me, he's playing midfielder with his partners in crime, creating that little diamond.
"Really, I want him [at striker], when we're one vs one. He's not allowing me to do that. Me and Nemanja [Vidic] are looking at each other and going 'we're not even part of the game. We're not even affecting it. He's sapping our confidence with even going past us'.
"All of a sudden, he gets it and comes alive here [just in front of the centre-backs] and he's asking 'can you hang out with me?'
Football - Manchester United v FC Barcelona 2011 UEFA Champions League Final - Wembley Stadium, London, England - 10/11 - 28/5/11
Barcelona's Lionel Messi shakes hands with Manchester United's Rio Ferdinand after winning the Champions League final
Mandatory Credit: Action Images / Carl Recine
Livepic
"And the moment you do that, these guys [the wingers] are running in here [behind the defence]. He creates so many problems for you without being physically against you. He's asking you do many questions. It's very difficult but it's all down to communication. If you communicate right, you've got a chance."
On whether himself and Vidic could have got tighter to Messi, he replied: "You can go tight on him when there's a lot of pressure on the ball and the person on the ball's head is down.
"Once the ball goes into his feet, you are now at the mercy of Mr Lionel Messi."
On Messi's positioning for his goal, Ferdinand added: "When young kids are playing as a number nine or number 10, they usually get dragged to the ball. He [Messi] is going and thinking 'where's the space away from the ball where people can't get at me? I don't want to go into traffic. I want to go out where there's no-one.'
"That's the patience and discipline of someone like Messi. He comes in and all of a sudden does his damage. It's a great goal."
Fascinating. Ferdinand was one of the best defenders of the 21st century and his comments show just how hard it is to mark the Argentine maestro.