Key figures including Sean Raggett, Marlon Pack and Tom Lowery are all signed on for next season, while Joe Morrell and Colby Bishop are the Blues’ most prized assets going into the window.
Connor Ogilvie, Josh Oluwayemi and Harry Jewitt-White all had options triggered by the club at the end of the campaign, while Ronan Curtis and Jay Mingi remain in negotiations.
At least 9-10 new faces have been pencilled in to arrive through the doors at Fratton Park in the window in John Mousinho’s maiden summer in charge.
But how much work do Pompey need to do compared to their rivals?
We’ve taken a look at the current squad sizes of each League One club to discover how many players they have under contract following the release of their retained lists.
NOTE: Carlisle and Barnsley are yet to publish their retained list due to involvement in the play-off final.
1. League One squad sizes
The current squad sizes of every League One side. Photo: Jason Brown
2. Stevenage
Current squad size: 7; Players under contract: Kane Smith, Kane Smith, Dan Sweeney, Carl Piergianni, Jordan Roberts, Jamie Reid, Elliott List, Danny Rose. Photo: Pete Norton
3. Burton
Current squad size: 8; Players under contract: Joe Powell, Josh Walker, Mark Helm, Sam Hughes, John Brayford, Bobby Kamwa, Ciaran Gilligan, Charlie Lakin. Photo: Nathan Stirk
4. Port Vale
Current squad size: 10; Players under contract: Aidan Stone, Lewis Cass, Nathan Smith, Tom Conlon, Funso Ojo, Will Forrester, Gavin Massey, Ellis Harrison, Tommy McDermott, James Plant. Photo: Morgan Harlow