Andy Awford has decided on his Pompey starting line-up for the August 9 kick-off.
But he is adamant his selection policy will operate on a game-by-game basis.
The Blues have been revamped by Awford during the summer with eight new arrivals giving a healthy-looking squad of 29.
The Pompey manager has plenty to contemplate heading into the League Two opener at Exeter in 16 days’ time.
His options will not include injured duo Wes Fogden and Tom Craddock, while David Connolly will not be considered.
Regardless, Awford has already made up his mind on his XI at St James Park.
He said: ‘I’ve got an idea of the team in my head but obviously you get your niggles and bumps, as we saw on Tuesday night. If we were playing Exeter tomorrow, I know what my team would be, definitely.
‘What I would say is although they are all fighting for the shirt against Exeter, I might need a different team against Peterborough to beat them.
‘I am not one to make too many changes.
‘Once I have got my team and they are winning then I don’t tend to change it too much.
‘But if we need to change for Peterborough or Cambridge then we will.
‘It might need a tinker or a slightly different approach, so they have all got to be ready.
‘And that is the one thing I have been emphasising to them since we came back.
‘As a group we will all play our part and I want to make sure that happens.
‘So it’s still all to play for – and players surprise you sometimes.’
Of the new recruits, Paul Jones, Danny Hollands, James Dunne and Craig Westcarr will surely feature in that first starting line-up.
Fellow fresh arrivals Nigel Atangana, Alex Wynter, Miles Storey and Michael Poke are also pushing hard for selection.
And Awford has pinpointed the impact of the youngsters he fielded in the 2-0 win at Thurrock on Tuesday as proof he can be persuaded.
He added: ‘I thought all the young kids did brilliantly on Tuesday night.
‘Nick (Awford) came on in the second half, put his foot in and made a difference, Ben Close got forward, the two boys in the first half at centre half (Jack Whatmough and Adam Webster) looked composed and competed really well.
‘Alex Wynter came through 90 minutes and did really well and Dan Butler had a right good assured game at left-back.
‘Jed (Wallace) has got a bit frustrated at times but is a massive threat with his pace, Miles Storey as well.
‘The youngsters have really come into the fray and given themselves every chance.’
Meanwhile, Bradley Tarbuck yesterday left Pompey’s training camp to return home for treatment on his injury.
The Emsworth youngster turned his ankle against Thurrock.