Pep Guardiola could be about to face his biggest Man City challenge yet

There are two options when you finish a game to completion: You can either walk away forever with the immense satisfaction of a job well done or you immediately go back to the beginning, ramp up the difficulty and start all over again. There are no prizes for guessing which one Pep Guardiola would do.

The Manchester City boss could retire from football today and he would go down as the greatest manager of his generation and perhaps of all time. Not only has he changed how the game is played from the grandest stage all the way down to the grottiest park pitches but he has won all there is to win in three different countries.

Guardiola's latest and possibly grandest achievement came just a couple of weeks ago when he guided his City side, which many had written off by mid-February, to a remarkable Treble triumph. Finally lifting the elusive Champions League trophy again after a 12-year wait.

Much like Lionel Messi's World Cup win being the unnecessary but satisfying final marker of greatness on his career, City's European success was the long-awaited proof of the truth everyone already knew: City are the best and they are managed by the best.

Also read: UEFA president admits Champions League final 'not perfect' for City fans

After such a crowning achievement it would be easy for Guardiola to call it a day there. Had City beaten Chelsea in the Champions League final two years ago, with his contract about to expire, he may well have left having won it all. But now he has two years remaining and he will honour them.

So how do things stay interesting after reaching the pinnacle? Well, there is the aim of winning an unprecedented quadruple after that accomplishment was scoured by Nathan Jones of all people. But before