Ryan Shawcross has had his Stoke contract terminated by mutual consent to bring an end to his 14 years with the club.
The 33-year-old made over 400 appearances for the Potters - most of them as captain - after arriving from Manchester United in 2007.
But he had seen reduced game-time in recent seasons after an injury ravaged 18-month spell following a broken leg in the summer of 2019.
He had found himself behind Republic of Ireland Under-21 international Nathan Collins in the defensive pecking order.
Collins (19) has made 27 appearances in all competitions this season but the Leixlip-born player is set for an extended spell on the sidelines after fracturing a bone his left foot in Saturday's defeat to Norwich.
In a club statement, Stoke said Shawcross had left "to allow him to pursue new playing opportunities in the United States". The player has been linked with a move to David Beckham's Inter Miami outfit in Major League Soccer.
Stoke chief executive Tony Scholes told the club's official website: "Ryan's contribution to the club over the last 14 years simply cannot be under-estimated. His outstanding leadership and the consistency of his displays made him a talismanic figure for us.
"He has been an outstanding role-model, both on and off the pitch, and the way he applied himself in training and matches epitomised the city of Stoke-on-Trent - hard-working, committed and loyal.
"He feels the time is right to explore new opportunities and leaves with our very best wishes. I would like to take this opportunity to wish Ryan, his wife Kath and their family every success for the future - they will always be welcome at the bet365 Stadium."
Stoke were promoted to the Premier League in Shawcross' first season at the club and he was a key part of Tony Pulis' side which established themselves in the top flight.
After being appointed club captain in 2010, Shawcross led his side to the 2011 FA Cup final, where they were beaten by Manchester City.
However, Shawcross made only eight first-team appearances after breaking his leg in July 2019.
Stoke manager Michael O'Neill added: "Before I came to Stoke City the one player you immediately associated with the club when it came up in conversation was Ryan, simply because of the length of time he spent here.
"It's very rare these days for a player to stay at one club for 14 years; I'm sure Ryan has had opportunities to go elsewhere down the years but he clearly felt settled and valued here.
"He hasn't figured as often as he would have liked over the past couple of years but his professionalism and the way he has conducted himself, both on the training ground and around the club, since I joined simply cannot be questioned."
Meanwhile, the former Northern Ireland manager added that Collins is likely to be sidelined for up to two months due to his foot fracture.
"Nathan has a fracture in his foot, which will probably keep him out for a large part of the remainder of the season to be honest," he said.
"We'll have to just assess that but it won’t be something that he’ll be back from in a couple of weeks.
"He has also undergone a scan just to check that there’s no additional ligament damage in that area which would make it a little bit more complex.
"But he has basically a fracture in the base of his foot and he'll be a minimum, I’d suggest, of six to eight weeks."
With Ireland's 2022 World Cup qualifying campaign beginning on 24 March, the injury is set to rule Collins out of consideration for Stephen Kenny's squad.