In total 12 senior players from Danny Cowley’s side – including those currently on loan at Fratton Park – will see their existing deals expire at the end of the season – with key players such as Sean Raggett, Marcus Harness and Michael Jacobs among them.
Meanwhile, across the EFL, there are plenty of former Blues stars in a similar boat to the present Fratton Park crop.
With another busy summer of transfer activity expected, could Cowley bring one of these potential free agents back to PO4?
You can decide as we take a look at the 23 former Pompey men who are set to be out of contract at the end of the campaign.
5. Stuart O'Keefe - Gillingham
The midfielder signed a one-year extension last summer but finds himself again out of contract this year. The 31-year-old has featured 39 times for the Gills this season as they target League One safety. Photo: Jason Brown
6. Jason Pearce - Charlton
The Charlton captain had been linked with a return to Fratton Park in 2019 and has always been open to a reunion. The 34-year-old centre-back hasn’t featured much this term, managing to make only 18 appearances to date. Photo: James Chance
7. Joe Mattock - Rotherham
The left-back may be one of the 'forgotten men' to play for Pompey after making only eight appearances for the Blues in the 2011-12 season. However, he has since established himself as a centre-back for Rotherham and has played 16 times this campaign as the Millers bid for promotion. Photo: Allan Hutchings
8. Adam May - Cambridge
The Pompey academy graduate signed a one-year extension last summer and again finds himself with an unclear future next term. The midfielder has impressed this campaign, playing a key role in Cambridge’s first season back in League One. Photo: PAUL ELLIS