Manchester City travel to Stamford Bridge this evening for a mouth-watering clash with Chelsea that could decide the destination of the Premier League title.
With City currently five points behind the leaders, a victory for the home side would see Manuel Pellegrini's reigning champions eight points adrift of top spot as they chase back-to-back Premier League titles for the first time in their history.
Of course, mathematically City will still be in the title race, with both teams having another 15 league games remaining after Saturday's showdown.
However, it's hard to see Jose Mourinho's stubborn outfit allowing City to claw back an eight point deficit for a second time this season.
With that in mind, a City defeat will leave Pellegrini with no other choice than to focus all attention on next month's huge Champions League tie with Barcelona.
The two teams have been drawn together in the round of 16 for the second consecutive season, and City will be desperate to improve on last year's 4-1 defeat.
To do so, City will need to relinquish their Premier League ambitions and put full focus on their Champions League dream.
Barca are beatable
A trip to the Nou Camp is an intimidating one for any club, but City will be buoyed by the fact Luis Enrique's side have already been beaten at their iconic home this season.
What's more, it wasn't Real or Atletico Madrid who took three points away from Catalonia, it was mid-table Celta Vigo.
That allows Pellegrini to go in to the away leg knowing anything is possible, but first, he has to take care of things on his own patch.
With the first leg taking place at the Etihad Stadium, City have the chance to take a positive result in to the second game.
To do so they'll need to keep Lionel Messi quiet, but if Vincent Kompany is at his outstanding best, City have every chance of causing trouble at the other end of the field.
Premier League is less important
The idea of giving up the title race to Mourinho's men is one that would undoubtedly anger City fans, but the reality is that the Champions League is the one the club's hierarchy really want.
With so much ground to make up on the leaders, City simply cannot both progress in Europe and overtake Chelsea to retain their title.
Their attempts to keep up with the Blues have already seen them dumped out of both the FA Cup and League Cup, to now drop out of the Champions League would be disastrous.
Since the day Sheikh Mansour took control of the club, becoming champions of Europe has been the dream, and if that means a second-placed league finish then so be it.
They have the players to win it
For some, City reigning Europe is an implausible idea; they'd believe City just don't have what it takes to win club football's most prestigious trophy.
However, in Yaya Toure, Sergio Aguero and Kompany they have some of the most outstanding individuals in their respective positions.
Stand out performances from any one of their world class stars could be enough to win a game on it's own, giving City the belief they can go all the way.
The usual faces will be standing in their way - Real, Bayern Munich and Chelsea all have realistic aims to be crowned champions of Europe.
But if City are serious about becoming one of the world's biggest clubs, which is surely Mansour's aim, they have to find a way to compete with those already at the top.
If that means relying on individual players rather than a world class team, then so be it, and while they're understandably outsiders for the competition, you'd be foolish to write them off just yet.