Among those are the likes of Sean Raggett, Marlon Pack and Joe Rafferty as well as Joe Morrell and Colby Bishop, who have both been linked with Championship switches.
It comes after eight members of the head coach’s side were released at the end of the season following a disappointing eighth-placed finish in League One.
Names including Clark Robertson and Michael Jacobs departed, while Ronan Curtis and Jay Mingi remain in negotiations over fresh terms.
But as Mousinho readies his squad ahead of a potential promotion push, what is the current state of play regarding contracts?
We’ve taken a look at each individual who has a deal beyond this summer and their latest situation at Fratton Park.
Here’s what we found.
13. Tom Lowery
Pompey fans failed to see the best in the midfielder during his first season at PO4 after injuries sidelined him for nearly six months. He arrived as a free agent in August 2022, where he signed a three-year deal which is set to run until 2025. Photo: Jason Brown
14. Harry Jewitt-White
The academy graduate had an option in his current deal triggered at the end of the season, which will keep him at Fratton until next summer. The midfielder has featured twice in the league under Mousinho. Photo: Jason Brown
15. Reeco Hackett
Hackett is in a similar situation to Hume, with interest reportedly growing elsewhere. His current deal runs out in 2024 after he signed a two-year contract last summer. Photo: Graham Hunt
16. Paddy Lane
The 22-year-old is the newest member of the squad, arriving for an undisclosed fee on deadline day in January. He signed a three-and-a-half year deal, which will see him remain at Fratton Park until at least 2026. The winger has made 15 appearances to date and also netted on the final day against Wycombe. Photo: Jason Brown