The former England defender and his Manchester City boss clashed in the dressing room following a defeat at Liverpool in December 2024, with the confrontation captured for the four-part series "A Beautiful Obsession," which follows Guardiola's last two seasons at the Etihad.
Walker reacted angrily to criticism from Guardiola over one of the goals conceded to Liverpool, believing he was being singled out.
"If you keep saying my name every meeting, every f***ing thing, it's going to be impossible, you're going to get a reaction," Walker said.
Guardiola insisted he had actually been referring to Josko Gvardiol and that Walker had misunderstood him, but the defender was unconvinced.
"For f***s sake. Every f***ing meeting it's my name," he snapped.
Guardiola then suggested he might mention Walker's name often simply because he was the club's captain — a role the City boss had no direct say in during his early years in charge, when players themselves voted on who would wear the armband. Walker's response cut to the heart of the row: "Ok but maybe you didn't want me to be captain. You didn't want me to be your captain."
Just over a month after that clash, Walker told the club he wanted to move abroad and joined AC Milan on loan for the remainder of the season. The documentary also shows Guardiola addressing his squad before a game against Chelsea soon after Walker's departure, visibly frustrated by the timing of his exit.
"I'm incredibly sad about what happened with Kyle," he told his players. "It was so easy for him – f***ing hell – it was so easy for him to come to me [and say] 'I'm done'. But he did not behave as a captain to do it. He knows we are in the toughest moment of our lives. What did you do, my friends? What did you do with your captain?"
Pretending to remove his own armband, Guardiola added: "Tell me – he took it and put it here."
Walker completed that season at Milan before moving to Burnley last summer, ending an eight-year spell on City's books. Guardiola, for his final season in charge, chose to select the captain himself rather than leave it to a squad vote, handing the armband to Bernardo Silva — a decision he later described as one of the best he made during his time at the club.