Steve Cotterill has pleaded for permanent arrivals to rid Pompey of their 'quicksand' culture.
The Blues boss was today set to recruit Ritchie de Laet on loan from Manchester United until the end of the season.
The 22-year-old defender was believed to have trained with Pompey yesterday.
And the club were hopeful of completing the paperwork in time to enable the Belgian to be in the squad for tomorrow's trip to Nottingham Forest.
The latest arrival will take the number of loans at Fratton Park to four – all defenders.
But Cotterill believes Pompey need permanent deals if they are to have a bright future.
Last week he handed a list of three players to chief executive David Lampitt in the hope of bringing them to Fratton Park during this transfer window.
Pompey's manager remains unsure whether all three will come off.
But he insists it is imperative to bring in long-term arrivals rather than delve merely in the loan market if the club are to flourish.
Cotterill said: 'It is important we do a bit of shopping in this window just to carry on building this club.
'We can't be built on what we have been built on this season. We have been built on quicksand from the start.
'That's very, very difficult.
'We have inherited a situation so bare that we need to do a couple of permanent deals now so we do have some shape in our squad.
'Otherwise, come May, we are back to square one and have wasted 12 months and potentially a couple of opportunities.
'I would say at this moment in time hopefully something will happen during January for us with two out of three players we want, you never know.
'We might have to get the third at a later date.
'But if we don't get two of the three we want now we might get none of the three in the summer.
'We are only bargain shopping, that's where we are. I am not sure we can get all three in. I am not sure we can get two in for what we are working on.
'But, at the end of the day, if we were to get two they would be very good for us, very good.'
There are still 18 days to go before the transfer window shuts on Monday, January 31.
That's plenty of time for negotiations to be reached as Cotterill seeks to spend the 'little' transfer kitty at his disposal.
He still has another loan to use – making it number five.
De Laet is set to be his fourth loanee, with his deal expected to be completed today.
The Belgium international joined Manchester United in 2009 and has made three appearances for the Red Devils.
De Laet, who can play anywhere across the back four, has already been on loan at Sheffield United and Preston this season.
But because the latter was an emergency loan, he is free to move to Fratton Park on a temporary basis.