Raheem Sterling won nine major trophies with the Cityzens.
The 27-year-old signed for Chelsea this summer as he dropped down the pecking order at Manchester City ending his seven-year spell with the club.
With the World Cup incoming, Sterling believed it was the right move for him to gain more regular first-team football at Chelsea.
He said on Thursday: “I felt my game time at City was getting limited for different reasons and I couldn’t afford to waste more time.
“When I look back in the future, I never wanted to look back and see a rise then a decline. So my feeling was I needed to keep at the same level and a fresh challenge was needed.
“Since I was 17, I’ve been a regular starter and to get to the peak time in my career, not to be playing regularly was something I wouldn’t accept.
“My personality is to try to fight and change the scenario but it didn’t come and that was it. With the few other options I had, this one was more tailor-made for my personal goals.
“I know exactly what I what from my life and football. So it’s a perfect time to have a new challenge.”