The 29-year-old had planned for some time to see out his current deal, announcing in The Telegraph in Novermber 2020: “We've had two transfer windows now where the club have decided, for whatever reason, that whatever has been offered on the table hasn't been enough and that's fine because I signed a contract for four-and-a-half years.
"So I won't whinge or not turn up, I just need to deal with it and get on with my football.
"But the longer my contract runs down, I feel I gain the control of my career more than Burnley having the control of it, which is what I feel like I need right now."
The centre back joined the Clarets for £3m from Brentford in January 2016, as the club were on the way to the Championship title, and he spent six seasons in the Premier League, earning two England caps in 2018.
And he posted a message to the Burnley fans on Instagram on Friday night: “An incredible six and a half years comes to an end. I’ve loved every minute of playing for this fantastic football club.
“So grateful I was given for the opportunity to join and live my dream of playing in the Premier League. Going to miss all the brothers I have gained over the years, what a pleasure it has been.
“I hope to see this club back where it belongs in the near future. I’ll be back at Turf Moor cheering on the Clarets at every opportunity I get. Thanks for everything.”