Cristiano Ronaldo and Jose Mourinho could have been one of the greatest player-manager combinations in football history.
'The Special One' was at the peak of his powers when he became Real Madrid manager in 2010, fresh from winning the Champions League with Inter Milan for the first treble in their history.
So, with the unlimited resources of Los Blancos at his fingers tips and a player only bettered at the time by Lionel Messi, everything was set up for unbridled success in the Spanish capital.
And in fairness, the 2011/12 season was more lucrative than most fans would have you know with Real romping to the La Liga crown over Pep Guardiola's Barcelona with a record 100 points.
But just a few months on from a campaign that reaped 121(!!!) league goals, things had turned sour and Mourinho eventually departed in the summer of 2013 under a cloud of controversy.
The end of Mourinho's reign
Tiffs with Sergio Ramos and Iker Casillas had been touted in the Spanish media as well as claims that Ronaldo - the jewel in Real's crown - had lost faith in the Portuguese coach.
And while we'll never know what truly happened behind the scenes at the Bernabeu, Luka Modric's new autobiography - titled ' A modo mio' - has given us some of the best insight yet.
Corriere dello Sport have published a segment that details a clash between Mourinho and Ronaldo which apparently could have boiled over into a fight if teammates hadn't intervened.
Mourinho and Ronaldo's clash
Per a translation by The Sun, Modric wrote: "I was surprised by Mourinho's reaction. We were winning 2-0 in the Copa del Rey.
"Ronaldo did not chase the rivals on his throw-in and Jose was furious with Cristiano.
"The two fought for a long time on the field. After returning to the locker room at half-time, I saw Ronaldo desperate, on the verge of tears.
"He said, 'I do my best and he continues to criticise me.'
"Mourinho came in and began to criticise the Portuguese for his responsibility during the game.
"They became so hot that only the intervention of the team-mates avoided a real fight between them."
Wow, wow, wow.
It's well publicised that Mourinho isn't afraid to criticise his own players, but berating Ronaldo for not doing his defensive duties to the point he was nearly in tears seems a little extreme, that's for sure.
What could have been?
As much as Mourinho would like to believe no player is bigger than the club at Real, he was always playing a dangerous game by upsetting the player upon which they pinned their success.
And in the end, you have to feel as though Ronaldo had the last laugh, going on to win his first Champions League title at Real in the season following Mourinho's departure.
It's not hard to imagine an alternate reality where it was Mourinho standing alongside him as opposed to Carlo Ancelotti, though. What could have been?
