Spurs boss Mauricio Pochettino has revealed that Kyle Walker asked to leave the club in April with his side still in the race for the Premier League title.
The England international moved to Manchester City for £50m in the summer having excelled for Tottenham.
But Pochettino has spoken of an exchange between the two when Walker claimed that his "heart isn't here any more".
"Walker had just played back-to-back games for the national team," the Argentine coach said in a Daily Mail extract of Guillem Balague's new book Brave New World. "Our first match after his return was against Burnley. Trippier had been doing well in training for a few months and got the nod, meaning Walker was on the bench.
"We played Swansea on the Wednesday and Walker started. Trippier came back into the team to face Watford on the Saturday and was man of the match.
"We won all three fixtures and were happy to have two regular starters competing for a place, with both players looking fresh for the final stretch of the campaign.
"Walker came to my office after the Watford game. 'Gaffer, I've been at Tottenham for nine years. I've thought about it and my heart isn't here any more. Nor is my head. I've given all I have to give. I wanted to tell you before I tell my agent that I want to leave this summer.'
"'Kyle, you have to stay professional. There's a month and a half to go. We're battling for the Premier League and FA Cup. We have to be focused and finish the campaign strongly.'
"'OK, gaffer. But it's already decided.'
"'Well, that doesn't just depend on you or me. It depends on the club, above all. You've disappointed me because you've decided to tell me that you want to leave when there is a month and bit left in the competition... You could've sucked it up, kept quiet, trained, played and helped the team when not picked... and at the end of the season you could have come and told me.'
"Miguel was present. I always try to ensure there are witnesses during private conversations. I considered it to be an alarming lack of respect for his team-mates and a slap in the face for the club. None of that could be explained to the public at the time.
"I had to bite my tongue. From that point, the rumours started to proliferate."