Richie Barker has warned Pompey they could be left with players in the comfort zone thanks to their contracts.
The Blues manager has called for an overhaul of the deals handed out to the current squad.
Barker believes the agreements given to the players lack the incentives to keep them motivated.
Guy Whittingham and his team effectively built a squad from scratch in the summer after the club exited administration in April.
The majority of those arrivals were handed two-year deals, with Andy Barcham and Johnny Ertl given three-year agreements.
Barker said: ‘When I came here, one of the first things I noticed was there were no incentivised contracts.
‘They were all two or three-year contracts which they did not have to earn. I don’t like that.
‘I don’t like players being able to look and not even see where the end of their contracts are.
‘I want them to constantly play for one.
‘I don’t like it when you can sit in the comfort zone.
‘How do you remedy it? By trying to change it and put in incentivised contracts.
‘Then people have to play and have to earn a contract.
‘I want people who are motivated, not people who can’t see the end of their contracts.Two and three-year contracts? It can’t be right.’
Barker is not planning to attack players’ contracts until the club’s place in League Two for next season has been assured. But he knows it’s a subject which will need tackling moving forward.
And he feels there is a lot of hard work ahead on the issue.
Barker said: ‘I’m not really dealing with contracts at the minute.
‘I’ll talk about that when we get to 52 points – or whatever we need to get to.
‘For the time being the contracts I’ve sorted out with the players I’ve brought in were relevant to the players at that particular time.
‘Beyond that, I don’t think anyone, at the moment, can be in a position to talk about any kind of contract.
‘I think we all need to sit down as a football club and decide where we need to go with this in the future.
‘Because of the position we’re in at the moment, we need motivated players.
‘If someone ends up top scorer for you and player of the year for three years in a row, you could justify giving them a long contract.
‘If they are an asset to the club then yes but, until then, you should keep people motivated.
‘If you are Wayne Rooney you can get them to sign a five-year deal because they are worth £50m.
‘At this level, we need people who are motivated.
‘We need people who are fresh and hungry and want to work every day, not where they can’t see the end of their contract.
‘I didn’t think players at this level had long contracts – until I came here.’