That will include new-boy Liam Vincent, who is deemed to be one for the future, and Reeco Hackett-Fairchild, who spent a largely uneventful loan spell at Southend last season.
But with Ronan Curtis also attracting interest and Pompey open to offers for players, that figure could easily drop as Danny Cowley overhauls the playing squad he inherited from Kenny Jackett.
With that in mind, we look at those 13 players who are currently contracted to the Blues and assess what their futures might hold.
13. Reeco Hackett-Fairchild
The winger hasn't been around since Danny Cowley took over in March. He spent last out on loan - firstly at Bromley and then at Southend. Will be interesting to see if he's given a chance at Pompey next season, after arriving from Bromley in January 2020. Cowley has a good track record of developing raw talent but the forward's Roots Hall spell will have done little to boost his chances of challenging for a Pompey first-team spot. Photo: JPIMedia