Kenny Jackett has revealed Pompey remain in the market for one final summer signing.
But the Blues boss will wait on the outcome of Saturday’s trip to Blackpool before deciding whether to recruit another fresh face.
The transfer window for League One and League Two clubs closes on Monday at 5pm.
Pompey have already added eight new players over the summer, including substantial fees spent on John Marquis, Marcus Harness and Ellis Harrison.
Jackett insists his playing budget can accommodate one more recruit, not reliant on potential outgoings.
Herbie Kane is one player the Blues have monitored in recent weeks, although parent club Liverpool are now reluctant to initiate a loan.
Regardless, Pompey’s boss still has the green light to once more enter the market.
He said: ‘There certainly won't be anybody going out. Whether there is anyone coming in, I cannot say 100 per cent, but it’s unlikely.
‘There is still room in the budget, perhaps a loan, we will see after Saturday.
‘If circumstances go against us at Blackpool, we still have a couple of days, that’s why I’m not 100 per cent.
‘I will weigh it up again Saturday.
‘I would suggest things are going to be quiet. I don’t want to say “No, nothing’s happening” – then on Sunday morning need to react.
‘Any interest in players revolves around performance and strength. It does seem we’ve got good depth and a few players can play in a couple of positions, which you are going to need.
‘It is not necessarily one out to get one in either.
‘Probably if anybody comes in for Luke McGee, he’s maybe the obvious one to leave, but there has been no interest.
‘I don’t think Bryn Morris is going anywhere, we’ve had some interest, but he is injured at the moment.’
Of Pompey’s summer recruits to date, Ryan Williams, Sean Raggett and James Bolton have been dogged by injury.
But Jackett remains confident they will still make an impact.
He added: ‘Some of the boys have taken a little bit of time, with an injury or two to Raggett and an injury or two to Bolton.
‘Downing has been a bit more consistent and played all the games, so it has been easier for him to find his way and find his best.
‘Ryan Williams has been very disrupted, so the new guys have found it a little bit difficult really.
‘Having said that, they are not serious injuries and there's a majority of the season to go, so they can hit top form – they are capable of it.’