John Terry says he is "hurting" after leaving Aston Villa, having given "everything" in their failed bid to win promotion back to the Premier League.
Terry, 37, joined Villa on a one-year deal last summer after leaving Chelsea and was appointed captain.
The last of the ex-England defender's 36 appearances came in Saturday's play-off final loss to Fulham.
"I will look back on my time here and think about how close we were to reaching our goal," said Terry.
The ex-England captain said Villa manager Steve Bruce had been "instrumental" in him joining and had taught him things that will "stay with me forever".
He added: "I have given my everything this year both on and off the pitch and I'm still hurting today that we never managed to get back to the Premier League, where this club 100% belongs."
Terry, who said the club will "always have a place in my heart", did not clarify whether he will play on elsewhere.
'A massive miss' - Bruce
Bruce, whose own future is unclear, said: "I am extremely disappointed we're not in a position to keep John. As you might expect, he was fantastic both on and off the pitch. He will be a massive miss."
Before the play-off final he had said he hoped to retain the services of the central defender, who made 492 league appearances across 19 years for Chelsea.
Prior to joining Villa last year, Terry reportedly received an "eye-watering offer" from Turkish club Galatasaray, while there was "definite interest" from China and the United States.
He has also previously stated a desire to move into management, saying it would be "incredible" to manage his former side Chelsea once his playing career ends.
In a statement Villa said: "John is a true leader and was everything and more that we hoped. Hugely popular and influential in the dressing room, he played a real captain's role in creating the incredible bond the players shared with our supporters, and vice-versa."
Villa 'need to change a lot of things'
Terry's exit is likely to be the first of a busy summer at Villa Park after chairman Tony Xia said the club must "rethink not only the past two years but also the past 10 years".
Xia told the club website: "We are all aware we will face severe Financial Fair Play challenges next season. Villa needs to be a sustainable football club.
"We have been heavily investing for the past two seasons. However, the loss on Saturday means that we need to change a lot of things."
Under a new set of FFP regulations agreed in November 2014, Championship clubs are not permitted to lose more than £39m over a three-season period.
Xia, who bought the club in June 2016, has spent a large amount in his two years at the club, with Scott Hogan, Ross McCormack and Jonathan Kodjia all joining for fees in excess of £10m.
Bruce to stay on?
Villa boss Bruce said after Saturday's defeat that he would remain at the club "as long as those above me see I'm fit to do it".
The 57-year-old, who is on a rolling contract, has been in charge at Villa Park since replacing Roberto di Matteo in October 2016.
Xia thanked the former Birmingham, Wigan and Hull City boss for his efforts in 2017-18 - but did not confirm whether he intended to retain his services.
"I'm delighted to see that under Steve's management this season, we demonstrated character and unity. We fought like a team," he said.
"I want to thank Steve from the bottom of my heart, particularly for his remarkable level of professional focus despite losing his parents this year. With that, I would like to say thank you to Steve and his coaching staff once again for leading the team forward wholeheartedly throughout the season."