The Wales international came through the youth ranks at Stamford Bridge but was released as a 16-year-old as the club leapt into the Roman Abramovich era.
It was a change of ownership that ultimately ended current Foxes boss Claudio Ranieri's spell there as manager, though the Italian has gone on to redeem himself as the mastermind of Leicester's title charge.
And King has stated he will also enjoy particular satisfaction when he and his team-mates are granted a guard of honour ahead of Sunday's final match of the season in west London.
"Getting that medal, getting the trophy, last Saturday was the best day of my life," said King in an interview with the Daily Mail. "But this weekend will be special too."
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'It was the start of the Abramovich era and they said it wasn't good enough to be the best lad in London or even England any more.
"You had to be the best in Europe and they said they would be looking for someone else in my position.
"I took it on the chin. I could see it. They only kept three or four [players].
"I only have good memories from Chelsea but it's nice to go back as a Premier League champion to a club that kicked you out at 16."
Despite his jovial public persona, the gravity of Sunday's occasion will not be lost on Ranieri according to King, who has seen his manager become calmer with age.
"The manager is probably more keen to rub salt in the wounds than I am," the midfielder add. "The young players would be ball boys so I was always sitting near to Claudio or across the other side from him.
"I saw a lot of him. He used to be a lot more animated then. It is strange, having watched him give out tactics, and now it's turned full circle for him and for me."