Zlatan Ibrahimovic says that he turned from a cat into a lion after working under Jose Mourinho.
The Sweden international was managed by the current Chelsea coach at Inter Milan for a season before departing the San Siro for a dream move to Barcelona in 2009 - and the PSG star revealed no manager has ever got more from him than the Portuguese.
In a revealing interview with BBC Sport, Ibrahimovic said: "[Mourinho] turned me from a cat into a lion, dragged things out of me at Inter that no one had done before".
The 31-year-old also reserved special praise for the former England coach Fabio Capello, who managed Ibrahimovic while working as at Juventus, and described current boss Carlo Ancelotti as "the most fantastic man, almost like a father".
However, the striker had no words of praise for the former Barcelona boss Pep Guardiola, who took over at European champions Bayern Munich in the summer.
The two men famously fell out while working together at the Nou Camp - resulting in Ibrahimovic leaving the Catalan giants after just two seasons at the club - one of which was spent with AC Milan.
"I still don't know why, I may never," Ibrahimovic explained when asked why Guardiola stopped communicating with him. "I tried to make contact with him - but he didn't want to speak to me, he was avoiding me. I walked into a room, he was sitting there drinking his coffee. But he got up, didn't finish his coffee. I thought: 'I'm not the problem, he is the problem.' But there were no words, no answers, nothing."