Jamie Ashdown believes Pompey need 14 new players for next season.
The Blues goalkeeper feels Steve Cotterill requires a squad containing a minimum of 22 men for the new campaign.
And the 30-year-old reckons his manager will need to utilise the loan market once again to get that number of players in.
Cotterill has just eight men to call upon at present, with his players returning for pre-season training in 18 days.
The Blues boss is due to meet the club’s new owners this week to work out his transfer budget.
But with a new embargo hanging over the club’s head because of the ongoing Tal Ben Haim wrangle, Pompey face a huge squad shortage for the second season in a row.
Ashdown said: ‘It would be nice to have 20 players for the start of the season.
‘I think we are going to need a squad of 22. In this league nowadays, a squad of that number is the bare minimum, really.
‘We did well to deal with last season with the numbers we had.
‘We are looking to build on what we had.’
Pompey made full use of the loan market last season to boost their shortage of players.
Cotterill had his full complement of temporary additions in the shape of Greg Halford, Ibrahima Sonko, Jonathan Hogg, Ritchie de Laet, David Cotterill and Carl Dickinson.
Ashdown feels loans will again play a key role for his side.
He said: ‘It’s tough to get the mix right.
‘It might be a case of getting more loans in.
‘That might be a way around it, if we want to get the standard we need.’