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...
1. June 2015
Adam Webster shows his talented in the ring as Pompey are put through their paces at Ballys Boxing Gym in Fratton. Picture: Ian Hargreaves Photo: Ian Hargreaves
2. July 2012
Pompey boss Michael Appleton and coach Guy Whittingham oversee the first day of the pre-season in July 2012. Picture: Steve Reid (122332-910) Photo: Steve Reid
3. July 2008
Pompey's coaching team of Tony Adams, Paul Groves, Harry Redknapp and Joe Jordan on the first day back at Pompey training at Wellington Sports Ground, Eastleigh, in July 2008. Picture: Jonathan Brady Photo: JONATHAN BRADY
4. July 2013
Johnny Ertl on the first day of Pompey pre-season training at St John's College playing fields in July 2013. Picture: Allan Hutchings Photo: Allan Hutchings