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.
13. Sonny Bradley - Luton
The centre-back has developed into an established Championship centre-half. The 30-year-old has been a key figure in Luton’s back line this term as they bid for promotion to the Premier League - but is currently recovering from groin surgery. Photo: Joe Pepler
14. Taylor Seymour - Crawley
The young keeper made just one outing off the bench for Pompey in a 5-1 defeat to Peterborough in last season’s Papa John’s Trophy. He joined Crawley in January but is yet to play for John Yems' side. Photo: Portsmouth FC
15. John Marquis - Lincoln
The striker departed Fratton Park in January by joining Lincoln until the end of the season. He has since scored five goals in 14 outings for Michael Appleton’s side. Photo: Robin Jones
16. Kal Naismith - Luton
After being the Blues’ top scorer during the 2016-17 campaign as a forward, the Scot has been turned into a centre-back at Luton, playing a crucial role in the Hatters’ surprise promotion charge. Photo: Joe Pepler