Bertrand initially joined the Saints on loan from Chelsea in 2014 and made the move permanent the following year.
The 31-year-old has been a mainstay in Southampton’s left-back position ever since, amassing 240 appearances across all competitions in the process.
“After many months of hard decision making, I have decided to leave Southampton Football Club.
“This has only been decided in the last 48 hours and comments that I had not accepted an offer previously are not true.
“I want to thank all the fans for welcoming me to this football club and supporting me endlessly. All the support staff behind the scenes, I thank you.
“Also, special thanks to the Liebherr family. It is a shame I cannot experience a full crowd at St Mary’s one more time.
“As this year has shown us, football is nothing without the fans. Arriving at Southampton seven years ago, I soon realised what a family-orientated club this is. A true peoples’ club!
“I bought into the ‘Southampton Way’. A connected football club, built on solid foundations and ambition, with an attractive, attacking style of football.
“During my time here, there have been many battles and there have been many amazing moments along the way too. From finishing in the club’s highest position within the Premier League, to playing in two FA Cup semi-finals, to a Carabao Cup final, to me being voted to the Premier League Team of the Season.
“This has been a difficult decision for me, but the time has come for me to seek a new home that allows me the freedom to play and maximise my contribution to the team.
“This club is in great hands now with CEO Martin Semmens and Matt Crocker. I would like to thank them both for their efforts.
“Southampton Football Club will always have a special place in my heart and I hope the saying, ‘once a saint, always a saint’ still stands because I look forward to returning to this club one day, either behind the scenes or as a fan. Thanks again, keep marching on!”
Bertrand, a Champions League and Europa League winner with Chelsea, has been linked with Arsenal, Crystal Palace and AC Milan.
