And chief executive Andy Cullen admitted the Blues can ill afford a repeat of last year’s massive amount of player turnover at Fratton Park.
Pompey are preparing for a busy period of transfer activity, with the transfer window opening on June 10.
Cowley has already stated he would like to keep as many as 17 of the group of players he worked with this season.
Pompey have 12 players out of contract with 10 first-team members contracted for next season and five loanees returning to their parent clubs.
Cowley has made it clear he would like to retain the services of Leicester’s George Hirst and Blackburn’s Hayden Carter moving forward, after successful loan stays.
Pompey have taken up options on Louis Thompson and Marcus Harness, with Jayden Reid and Jay Mingi set to follow suit.
He said: ‘It’s not unrealistic (to keep 17 players) and it’s within our power to do that.
‘That number would have to be reached by getting some of the players we like to re-sign.
‘If we can get to that situation we’d be in a much better place than we were this time last year with out of contracts and players that would’ve preferred to move on.
‘At least a good majority of the players in the building at the moment have been signed by the club.
‘We hold one or two cards on that.
‘So is it realistic number? We’d certainly try to retain and keep the nucleus of the squad if we can.’
Cullen looked back to the recruitment work which was carried out last summer after Cowley’s March arrival and indicated that is a scenario Pompey will be keen to avoid a repeat of.
On that occasion 18 players left the club with 15 new additions arriving during a frenetic period of business.
On top of that, there was a constant stream of triallists coming into the club’s Roko training base to give Cowley a group of players to work with.
Cullen is clear that period was far from ideal but Pompey are in a better position now to ensure a chaotic period doesn’t take place again.
He added: ‘From June last year there were a lot of new faces coming into the building, either permanents or on loan. It was too much.
‘That is an inordinate amount of players for any club to integrate.
‘This year we have a bit more of a base, a few more in contract and options we’d like to exercise.
‘Then it’s strengthening and adding in the area identified and working with Danny on using the resources he has available.
‘Ultimately he will give the parameters and we will try to get the deals done for him.’