He left for Wolfsburg in January 2014 before moving to City in 2015.
"There was so much in the press about my relationship with Jose Mourinho," De Bruyne, 27. "But the truth is that I only ever spoke to him twice. The plan was always for me to go on loan for a bit."
De Bruyne scored 10 goals in 33 Bundesliga appearances for Werder Bremen before returning to Stamford Bridge, when the then Borussia Dortmund manager Jurgen Klopp - now in charge of City's title rivals Liverpool - wanted to sign him, writes BBC football.
De Bruyne said: "Mourinho texted me, 'You are staying. I want you to be part of this team'. "So I thought, OK, great. I'm in his plans."
De Bruyne started two of the first four league games of the 2013-14 season, but soon fell out of favour with Mourinho and was dropped to the bench.
"Jose called me into his office in December, and it was probably the second big life-changing moment for me. He had some papers in front of him, and he said, 'One assist. Zero goals. Ten recoveries'," De Bruyne said.
"It took me a minute to understand what he was doing. Then he started reading the stats of the other attacking forwards - Willian, Oscar, Mata, Schürrle. And it's like - five goals, 10 assists, whatever.
"Jose was just kind of waiting for me to say something, and finally I said, 'But… some of these guys have played 15, 20 games. I've only played three. So it's going to be different, no?'
"It was so strange. I was completely honest. I said, 'I feel like the club doesn't really want me here. I want to play football. I'd rather you sell me.'"
The following month, De Bruyne joined Wolfsburg for £18m.
He scored 13 goals in 51 league appearances before becoming City's record signing in 2015 when he agreed a £55m, six-year deal.