Names including Kyle Joseph, Aaron Collins and Matt Butcher have all been thrown into the rumour mill, alongside long-term targets Kyle Wootton and Will Boyle.
Danny Cowley has continued to pursue deals for Hayden Carter and 2021-22 top-scorer George Hirst to return to Fratton Park following their successful loans last term.
Yet, the Blues have completed just one signing to date, with Marlon Pack arriving on a two-year deal from Cardiff last week.
Meanwhile, as the transfer window ticks on, a number of those 25 names have found new homes away from Fratton Park.
Indeed, 11 have found themselves alternative destinations or signed new deals to stay at their respective clubs.
We’ve taken a look at where those names have ended up since their links to PO4.
Here’s what we found.
5. Will Boyle - Huddersfield
Boyle was another long-term target of Cowley, who viewed the centre-back as the best left-footed option in a back three. Following the season’s conclusion, The News claimed the Blues had cooled their interest, with the Pompey boss eyeing a right-footed defender as his next defensive move. Instead, the 26-year-old returned to Huddersfield - penning a two-year deal with a club option of a third. Photo: Pete Norton
6. Luke Molyneux - Doncaster
The Blues reportedly were battling League One rivals Derby to land the Hartlepool player of the season after he failed to agree new terms at the Suit Direct Stadium. The 24-year-old flourished in the Monkey Hangers’ first season back in the EFL, with the attacking midfielder scoring 12 goals in 55 outings last term. But it was Doncaster who fended off interest in Molyneux, who signed a two year deal last week. Photo: Pete Norton
7. Mickel Miller - Plymouth
The versatile winger is the latest player to be linked with a summer move to the Blues after the Sheffiled Star revealed Pompey, Plymouth, Burton and Lincoln were all keen on the Rotherham ace. But it was the Pilgrims who won the race for the 26-year-old after he completed a two-year deal at Home Park on Monday evening. Photo: Catherine Ivill
8. Cauley Woodrow - Luton
Pompey were linked with a surprise move for the Barnsley ace following their relegation to the Championship. The Blues were reportedly competing alongside Sheffield Wednesday and Ipswich before the Tykes gave Luton permission to speak to their star striker. The 27-year made a return to the Hatters after more than a decade away last week, signing for an undisclosed fee. Photo: George Wood