But Guy Whittingham insists that will suit him fine as he continues to work on deals.
The Blues boss had a maximum squad size of 20 this season under the restrictions of administration and so far has just three contracted players for next term - Ashley Harris, Adam Webster and Jed Wallace.
Under administration, any youngsters called into Pompey’s first-team were counted in their squad line-up. However, that will not be the case for next season, with Whittingham now having the freedom to boost his numbers from the Academy.
He explained: ‘I would think we’ll need in the first-team squad, discounting the ones we have in the development squad, 18-20 players for next season.
‘If we have 18 I’m not worried because I know there are one or two who are in the development squad who can be a part of it.
‘They will be supplementary to that number. But those are the numbers I’ll be working to.’
Whittingham has already had discussions with most of his current squad about staying and is keen to maintain the same blend of youth and experience in the ranks.
He said: ‘I think we have a fairly good balance in terms of age now. I wouldn’t picture it changing too much.
‘I don’t have a problem with the older players if they are like David Connolly who know how to look after themselves.
‘He’s always running around like a mad man, anyway.
‘If there’s an older player who is a good fit for us I’d have no problem with going down that road again.’