The Manchester derby was a whole other category for Sir Alex Ferguson. The significance of the local clash meant to him the same or even more than the match-ups against Liverpool.The Scot never missed a chance to let his players know that they will either follow him in his dedication to beating Manchester City or they will not step on the pitch under his managing.One of the players who felt his passion towards local dominance was the Dutch super striker Ruud van Nistelrooy. Rio Ferdinand spoke about how van Nistelrooy quickly realised the dos and don’ts when it comes to clashes with City.A ten-minute tactical preparation was all it took for Pep & Co to out-think their archrivalsJust four months after Ferdinand signed for Manchester United in July 2002 from Leeds United – he got his first taste of a Manchester derby as United travelled to City’s then-home-ground – Maine Road.The derby debut didn’t go to plan as Ferguson’s side were defeated 3-1. However, despite the pain of the defeat, it wasn’t until Ferdinand got into the changing rooms that he witnessed at first-hand what the derby should represent to United and anyone playing this derby under Ferguson.Ferdinand recalls van Nistelrooy’s appearance with a City shirt in his hand that sent Ferguson to state of utter rage.’We got beat 3-1 at Maine Road with Shaun Goater scoring two goals,’ Rio reflected on one specific incident.’That was the first derby I played and the moment I realised how big it was was in the changing room after.’We walked in and the manager shut the door. It was quiet and then all of a sudden he just erupted.Sir Alex confesses: Henry’s arrival at Arsenal turned my rivalry with Wenger toxic’Ruud van Nistelrooy, who was the God then, walked in with a City shirt in his hand and I remember Sir Alex Ferguson just absolutely unloaded on him. He destroyed him saying “if I ever see any of you walking with a City shirt ever again you’ll never play for this club”.’That’s how he was, he was just mad. That’s when I sat there and thought “this is a big game, isn’t it”. , he told while speaking with City legend Vincent Kompany as part of Ferdinand’s FIVE YouTube channel.’I didn’t realise before that game and ever since then, whether you win more or less, I knew that week leading up to a derby was all or nothing.’The ever controversial Warnock: Sir Alex is the fourth best boss of the Premier League eraIn the following Manchester derby, van Nistelrooy sort of redeemed himself by scoring a goal but it was not a winner – Sky Blues equalised in the 86th minute of the match. We can only imagine what Sir Alex said to his players in the dressing room afterwards.