In total, 11 members of the Blues’ current squad’s deals expire – including the likes of Tom Naylor, Jack Whatmough and Ben Close.
Head coach Danny Cowley’s already confirmed that Duncan Turnbull’s time on the south coast has come to an end, having joined American outfit Las Vegas Lights on loan.
However, there are plenty of former Pompeymen in a similar situation.
A host of ex-Blues players’ contracts up and down the country are also set to come to a close in June and some will likely be on the move during the summer transfer window.
Here’s a look at those whose futures are uncertain…
5. Adam May - Cambridge
The academy product's scored three goals in 45 games during Cambridge's League Two title push. The U's hold an option of an additional year in his contract following his arrival last summer. Photo: Joe Pepler
6. Dion Donohue - Barrow
The versatile left-footer quit Swindon midway through the season to be closer to his family in the north. However, he's not featured for Barrow since February. Photo: Joe Pepler
7. Nicke Kabamba - Kilmarnock
The striker has netted five times in 34 games for the Scottish Premiership outfit this season. Photo: .
8. John Akinde - Gillingham
The striker's bagged seven goals in 49 games for the Gills this term. He played under Danny Cowley at Lincoln. Photo: Barry Zee