Instead he has stressed the ability to recruit during this transfer window is far more complex.
The settlement of Drew Talbot’s contract and end of Damien McCrory’s loan spell has created space in Kenny Jackett’s squad.
It represents crucial movement within the playing budget to patch up his injury-hit options.
For much of his time at Fratton Park, Jackett has been challenged to dispose of players before bringing new faces to the south coast.
That continues to be the case following the opening of the current transfer window.
However, Pompey’s chief executive insists the recruitment process is not as simple as often perceived.
Catlin said: ‘I don’t think you can say there is one out, one in because players are on different salaries.
‘For example, you could get two players out to be able to get one in – or one out to get four in. A lot depends on the deals you do with other clubs, it’s not purely a case of manpower because people are on different salaries.
‘So it’s not a simple case of saying “one out, one in”. It depends on the wages freed up and deals you can do at other clubs, specifically on loan.
‘Damien (McCrory) was only ever budgeted for January anyway because that is when his loan ended.
‘Although Drew leaving has created a little bit of wriggle room there.
‘But it’s not as easy as one out, one in.’
The previous transfer window saw a hectic deadline day for the Blues, with four departing and four arriving.
It represented a balancing act for Jackett as he sought to strengthen his playing squad with the arrivals of Stuart O’Keefe, Matty Kennedy, Oli Hawkins and McCrory.
Exiting Fratton Park on that final day were Michael Smith, Nicke Kabamba (loan), Tom Davies and Carl Baker.
A similar bout of juggling must take place during the present month, with Pompey retaining an important proportion of self-control.
Catlin added: ‘Even if we decide to strengthen in a specific area, I can assure you 100 per cent we will not be going crazy.
‘It will be slight, there will be no massive throwing money at it this January transfer window.
‘If there is an extreme circumstance that needs to be addressed then I am sure it will be looked at.’