The opening two days involve medical and physical testing, with the team coming together for full training on Thursday morning at their Hilsea training base.
We’ve dipped into the picture archives to look at first days of Pompey pre-season training from the past, with a host of familiar faces in action.
Hope you enjoy the trip down memory lane far more than those players partaking in them...
9. July 2015
Adam McGurk and Adam Webster pictured as Pompey's squad are put through their paces at Ballys Boxing Gym in Fratton in July 2015. Picture Ian Hargreaves Photo: Ian Hargreaves
10. June 2022
Pompey players back for pre-season training under Danny Cowley in June 2022. Picture: Habibur Rahman Photo: Habibur Rahman
11. May 2016
Pompey's squad gather ahead of pre-season running in Portchester in May 2016. Picture: Ian Hargreaves Photo: Ian Hargreaves
12. July 2007
Matt Taylor, Djimi Traore, Pedro Mendes and Sylvain Distin is pre-season training in July 2007. Picture: Steve Reid Photo: Steve Reid