Ruud van Nistelrooy was one of the best strikers of his generation.The Dutchman played for some of the world's biggest teams, including Manchester United and Real Madrid, scoring goals at will.It was at the English giants where he was at his peak.Van Nistelrooy scored 150 times in 219 games for the Red Devils as he tormented opposition defenders in England and across Europe.Ruud van Nistelrooy in action for Man United vs AC MilanBut there is one side which Van Nistelrooy did not have much joy against: AC Milan.Back in 2005, Man United played against AC Milan in the Champions League last-16.That AC Milan side was packed with incredible players all over the pitch, including Paolo Maldini, Cafu, Kaka and Clarence Seedorf.p1fbuh8n851vtfkfd12ijrk1a9df.jpgENTER GIVEAWAYAnd Van Nistelrooy was left frustrated as AC Milan won 2-0 on aggregate to progress to the quarter-finals.Van Nistelrooy has since spoken out about just how good that side was as he recalled the game at the San Siro.In a viral video created by Twitter user @Futball_Karim, Van Nistelrooy says: "I played against AC Milan at the San Siro and there was a back four of Cafu, Jaap Stam, [Paolo] Maldini and [Alessandro] Nesta.

"So I was just like... that is interesting you know. Ok... They were pretty good. All four of them and how they worked as a unit. 

"There was Gattuso just in front. You know he's like 'I'm going to kill you every time you get the ball'.

"And then Pirlo... he's fantastic. [Clarance] Seedorf was playing in that team too. Strongest man in the world.

Will Kieran Trippier be Man United's next done deal?! Find out on The Football Terrace...

"I didn't score that game. I couldn't. I couldn't get near a shot. Like 4/5 players flying in which I had the ball. That was pretty amazing."

That team was just incredible. The fact that AC Milan side kept a prime Van Nistelrooy quiet over two legs show just how good they were.