Of course, the Blues could well plunder Premier League and Championship academies for loan gems to get their final players in before September 1.
But Danny Cowley has hinted there is a deal advanced for a young talent operating at a lower level.
So we’ve looked at some of the hottest prospects from around League Two and the National League who could be interesting Pompey and their rivals.
1. John McAtee
A deep-lying striker, the 23-year-old impressed with Grimsby last term producing 16 goals and eight assists for the Mariners. Photo: Justin Setterfield
2. Ruben Rodrigues
A player Danny Cowley will know all about having watched Notts County a fair amount last term. Can play as an attacking midfielder or striker - hit 20 goals and six assists in the National League last term. Photo: Laurence Griffiths
3. Olly Dyson
Known for his versatility, the 22-year-old can play right-back, ring wing or in the middle of the park and delivered eight National League assists last season. Photo: Julian Finney
4. Greg Olley
Wyscout shows an off-the-chart assist return for the Gateshead winger last term, with the former Newcastle talent returning a whopping 20 assists in the National League North. Photo: Stu Forster