The 28-year old notched up just five caps in his first five years, but in the last five has collected a further 41.
He said: "When I was at Chelsea, the England manager Sven- Goran Eriksson said to me that he wanted to pick me but he couldn't because I wasn't playing regular first-team football.
"So if I had been playing more regular football, I probably would have got even more caps. That obviously wasn't to be. But I made my decision that I needed to leave Chelsea.
"I knew I was capable of playing at this level but I had to prove it and I had to leave Chelsea to do that."