SUNDAY’S Manchester derby is the biggest league game in the world.

A bold statement no doubt, but when you look at any other game that might come close to it the United-City showdown is just plain bigger.

It is not just the fact it is the top two in the Premier League – that’s been the case before.

It’s what it could mean to English football in the future should Jose Mourinho’s Reds not get the better of Pep Guardiola’s Blues.

The only other game that could knock this Old Trafford clash off its perch is El Clasico.

Real Madrid versus Barcelona has always been seen as being in a world of its own in terms of the global scale of the contest.

But unless Real buck up, any La Liga game between the two will be more about whether they can prevent Barca from winning the league rather than finishing top of the pile themselves.

They are currently in fourth place, eight points behind their traditional rivals.

United are the same number of points behind City in the Premier League going into Sunday’s derby but they are in second place and reckoned to be the main challengers.

While many, if not most, United supporters still regard Liverpool as their biggest rivals, Sunday’s game against City is more important as a sporting contest.

Good team as Liverpool are, the chances of them winning the league title this year are as likely as their fans holding a Christmas party at Old Trafford.

First place this year is almost certain to be one of the Manchester clubs. If City win on Sunday the odds against them finishing top of the pile for the third time is six years will hardly be worth betting on.

As the Premier League is the most watched, and widely regarded as the most exciting and important league in the world, Sunday’s game reaches a new level of importance.

It features the two highest-profile managers in the world and two teams in the midst of remarkable records with United unbeaten in 40 home games and City looking to break the Premier League record of successive wins in one season with a 14th.

But it is not only the destination of this season’s title on which Sunday’s derby could have a bearing, but where the balance of power is likely to be for the next few years.

Guardiola and City appear to be settling into a powerful stride which shows no sign of relenting whereas Mourinho may struggle to close the gap in the future given his history of struggling in his third season and rarely staying at any one club for much longer.

Chelsea have taken a step backwards since last season, Arsenal have become serial title non-competitors while Tottenham’s comparatively modest wage structure will make it difficult for them to keep their best players.

Those signs all point to the Manchester clubs continuing to dominate with City’s stability of style, players and management – not to mention their seemingly bottomless financial muscle – putting their noses in front of their cross-city neighbours.

Should City break that successive wins record on Sunday they will not only look set fair for this season’s title but also to dominate in future years.

For that reason there will be many neutrals finding themselves in the unusual position of wanting United to win.