Pompey will seek permission from the Republic of Ireland for Ronan Curtis to feature against Gillingham.
That’s provided the winger has recovered from the hamstring scare which prompted his withdrawal from international duty.
Curtis had been scheduled to link up with Mick McCarthy's squad on Sunday, ahead of Euro 2020 qualifiers against Georgia (October 12) and Switzerland (October 15).
However, he complained of a tight hamstring during Pompey training on Friday, forcing his absence from the subsequent 2-1 victory at Doncaster.
Kenny Jackett is awaiting the outcome of a scan to discover the extent of damage to the 23-year-old.
If declared fit, the Blues will attempt to clarify Curtis’ availability with the Football Association of Ireland for Saturday’s visit of Gillingham.
Ironically, it's a fixture which Pompey had the option of postponing due to Curtis’ Irish call-up in the first place.
Jackett said: 'We wanted to play against Gillingham, even if we had three players away on international duty.
‘So if Ronan is fit by the end of the week can he now play? I don’t know the answer to that.
‘I would suggest he probably needs permission from Ireland, he is their player over the international period, they are the rules.
‘There are grey areas there. Regardless, I wanted to play the Gillingham game with three players away.
‘I’m not sure whether having one of our players pull out of international duty to injury would have taken away that postponement option.
‘That would have left us with two away, with Ronan now injured. You need three for a postponement, of course.
‘Can Ronan be fit for the weekend? If he’s fit, if he's okay, that’s great, but is he available?
‘I would suggest we need to get permission.’
Curtis’ withdrawal leaves Craig MacGillivray (Scotland) and Ross McCrorie (Scotland under-21s) absent from Blues duty this week.
Last month, international call-ups prompted the postponement of Southend’s visit.
But Jackett wanted to fulfil the Gillingham fixture.
He added: ‘Last time we had three call-ups, plus Marcus Harness came off injured at Blackpool and Lee Brown was already out. I didn't think there was any choice.
‘But the gaps between league games haven’t helped us. By the time the next game comes around there is too much anxiety in the players. Even if there’s a cup game in between it affects a bit of flow.
‘The pressure, the anxiety, the way it builds up with 14 days from one league game to another is very unusual.
‘It’s nobody's fault, similarly it’s hard for the players to get into a rhythm, while builds up quite a bit of pressure.’