Aguero discusses the pair in his book, 'My Story':
"His relationship with Mancini often made me smile. They would fight like cat and dog during training and then walk off with their arms around each other's shoulders. They would swear and shout at each other, but later they'd be like father and son. Quite often we'd have five-a-sides in training and Mancini would join in. He would make sure he was on the opposite side to Mario so they could wind each other up. He'd tell Mario and the rest of us that he wasn't the manager in the game, just another player.
"He said we could say what we wanted to him and it would be fine so the game would begin and Mancini and Mario would be at each other, kicking lumps out of one another and shouting abuse until the final whistle when Mancini would say, 'Right, I'm your manager again, now!
"Mario would say, 'You were sh** when you were a player... and it was a lot easier then than it is now.' Mancini would say, 'You wouldn't have been able to play then or now!' It was comical. Mario would go away and sulk for a couple of days and he was just like a little kid. I miss him being around the place because even though he was a little crazy, he was a great character to have around the dressing room."
For the big stories and the banter follow us on Twitter: @tribalfootball