Mesut Ozil says Jose Mourinho once accused him of being a "coward" and "too nice to tackle" in a dressing room argument during their time at Real Madrid.
The Arsenal midfielder describes the incident in his upcoming autobiography, saying Mourinho called him out in front of the entire team during the half-time break of one game after he had failed to exert enough influence.
In an excerpt published in German magazine Bild, Ozil writes that Mourinho told him: "You think two beautiful passes are enough ... You think you're so good that fifty percent is enough. You think you are too nice to tackle."
Mourinho then added: "Do you know what your tackling looks like? No? I'll show you."
And then, Ozil writes, Mourinho tiptoed in front of Ozil with his hands close to his side with pursed lips and proceeded to hop all over the changing room.
Ozil, who played under Mourinho at Madrid from 2010 and 2013, compares the tense encounter to "two boxers at the stare-down before the first round."
He added: "He shows no emotion. Just waits for a response from me. How much I hate him right now. And I love Mourinho actually."
Finally a furious Ozil threw his shirt at Mourinho and challenged him to go out and play himself.
Mourinho is then said to have taunted him by saying: "Oh, are you giving up now? You're such a coward. What do you want? To creep under the beautiful, warm shower? Shampoo your hair? To be alone? Or do you want to prove to your fellow players, the fans out there, and me, what you can do."
The incident highlights Mourinho's willingness to confront his players in order to coax a better performance out of them.
Ozil has faced criticism for sub-par performances in big games this season, such as Arsenal's Premier League losses to Manchester City and Chelsea.
Arsene Wenger said after Arsenal's win over Hull last month that Ozil needed to regain his confidence, but has otherwise refused to criticise the playmaker in public.