Manchester United legend Gary Neville feels tomorrow's derby will set the Premier League scene for the next three years.
Neville can see Manchester City dominating the competition should they win the title this season.
He wrote in the Mail on Sunday: "Imagine what it would mean to Manchester City if they could win and go on to win the league? It would give the club and their players the sense of entitlement, confidence and belief that only comes with winning a title. Doing so against United would only add to that renewed sense of authority in the city and in the Premier League.
"They would have a hardness and toughness from staying the course over 38 games that would be added to their undoubted ability. And that would serve them well in the future.
"We've seen it with Arsenal and then Chelsea. Once you win one title, you often go on to win another.
"But imagine if they lost. Imagine if, having got back into the title race, they see United win the title at their own ground. That would only reinforce United's sense of superiority and City's feeling that they might never get one over their old rivals.
"With the financial backing they have, City will keep coming at United, of course. But psychologically it could be a telling blow."