Kenny Jackett has admitted he wants a new central midfielder.
Yet Pompey are unable to secure any target until members of the current playing squad depart.
The Blues remain keen, however, on strengthening an area which this summer lost Michael Doyle, Amine Linganzi and Stanley Aborah.
Presently, Carl Baker appears to be Jackett’s preferred choice after switching from the wing to partner Danny Rose.
The 34-year-old has impressed in the role during recent friendlies against Bournemouth and Crawley – and remains in the frame for Saturday’s League One opener.
Youngsters Adam May and Ben Close are the alternatives, but neither have been employed in the first-team’s past two outings.
Pompey’s boss has already recruited Nathan Thompson, Tareiq Holmes-Dennis, Luke McGee and Brett Pitman since taking over the helm.
But so far a fresh face in midfield has not arrived, despite the reduction in that area since claiming the League Two title.
Jackett said: ‘We are okay, there won’t be major changes in the next month.
‘If we had any players I think it would only be one, and if we do it would be more likely players will be going out first because it is a big squad.
‘Midfield is an area I have looked at.
‘On Saturday we had the two experienced lads in Baker and Rose playing there, while during pre-season Close and May have shown me good enthusiasm and good quality.
‘However, it is an area we are looking at in terms of players being able to help us win games.
‘We have not necessarily identified anyone, but we feel we have worked hard in training and there are players developing and players coming through.
‘And there are five midfield players at the club aged between 18-21.’
In terms of young midfielders at Fratton Park, Theo Widdrington has joined the Hawks on loan, while Jez Bedford is interesting Poole.
Pompey are also seeking to loan out Christian Oxlade-Chamberlain for a second successive season, following time at Eastbourne last term.
May has started ahead of Close on occasions during the pre-season, now both find themselves trailing the converted Baker.
Meanwhile, it will be the ever-reliable Danny Rose’s first campaign at League One level.