A number will have benefitted Pompey financially, with offers for the likes of Matt Clarke, Marcus Harness and Jamal Lowe too good to turn down.
Others, though, will have raised a few eyebrows and left many supporters disappointed.
Indeed, there’s quite a few departures that make you wonder ‘what if?’ if more of an effort had been made to retain certain individuals.
Here are 18 former Pompey players we believe fit into that latter category since the Blues returned to League One in 2017.
17. Hayden Carter
Danny Cowley made the defender one of his top targets last summer after the Rovers loanee impressed during a half-season stay at Fratton Park during the 2021-22 season. A £500,000 move was reported, while Carter himself said he would be open to a return. However, a desire to play Championship football at Ewood Park was getting in the way. Andrew Cullen added: 'Hayden is a player that everyone would love to have back at Fratton Park, not just myself and Danny, but the supporters as well. We’re in a situation with Blackburn where we were very grateful to them for entrusting the next stage of Hayden’s development with us in the second half of last season. I know they have big plans for him at Ewood Park and at the minute see him as a big part of their team going forward next year.' Photo: Paul Thompson
18. George Hirst
The on-loan Leicester forward ended last season with 15 goals in 46 appearances as he finished as Pompey’s top scorer. That impressive stint restored the reputation of Hirst, who had previously failed to score in 34 league appearances for Leicester, Sheffield Wednesday and Rotherham. As a consequence of his morale-boosted Pompey stint, he eyed the Championship as his next move rather than another season in League One with the Blues. He's back in League One now, though, after moving to Ipswich in January. Photo: Paul Thompson
19. Aiden O'Brien
Despite gaining cult-hero status at Pompey following five goals in 17 games over the second half of the 2021-22 campaign, the former Sunderland man departed after failing to agree terms on a new deal. He subsequently joined League One rivals Shrewsbury on a free transfer, signing a two-year contract. O'Brien moved to League Two Gillingham in January. His summer 2022 departure from Pompey meant the Blues have had just three recognised strikers in their ranks this season - Colby Bishop and loan duo Dane Scarlett and Joe Pigott. Photo: Paul Thompson