Abu, 21, signed from Chelsea two years ago and was integral to his side reaching the Premier League 2 play-off final.
The defender will leave St Mary's this summer, along with play-off final teammates Josh McNamara and Lewis Payne.
The Premier League have published retained and released lists for their 20 clubs following the conclusion of the 2024/25 season.
Goalkeeper Josh McNamara is set to leave the club _(Image: Craig Hobbs / Southampton FC)_
[For a full senior retained and released list, click here.](https://www.dailyecho.co.uk/sport/25225587.walker-peters-lumley-lallana-set-depart-southampton/)
**Saints youngsters retained**
_Professional contracts_
Romeo Akachukwu, Will Armitage, Zach Awe, Dom Ballard, Nat Boot, Cam Bragg, Brandon Charles, Sonnie Davis, Baylee Dipepa, Tommy Dobson-Ventura, Max Fry, Josh Jeffries, Nico Lawrence, Will Merry, Adli Mohamed, Jayden Moore, Brook Myers, Joe O'Brien-Whitmarsh, Khiani Shombe, Nick Oyekunle, Moses Sesay, Sam Tabares, Daouda Traore, Victor Udoh, Barnaby Williams, Ollie Wright.
_Scholars_
Hansel Adjei-Afriyie, Cameron Frederick, Harry Gathercole, Tino Goremusandu, Korban McMullan, Dylan Moody, Oli Newman, Thierry Rohart-Brown, Leo Umeh.
_Offered contracts_
Princewill Ehibatiomhan, Ben Reeves (player-coach), Aston Daley, Abdulhalim Okunola, Sufianu Silah Dibaga.
**Saints youngsters released**
_Professional contracts_
Derrick Abu, Josh Lett, Josh McNamara, Lewis Payne.
_Scholars_
James Martin, Tevin Myers, Alfie Prescott, Ben Sheaf, Harry Upstell.