Gareth Evans is expected to be fit for Pompey’s trip to Mansfield.
The midfielder had to be substituted at half-time against Newport after damaging his left ankle.
The 21st-minute challenge from Mark Byrne earned the Exiles’ skipper the game’s first yellow card.
Evans attempted to continue, but needed to be taken off at the break and has since yet to train.
However, first-team coach Ian Foster anticipates the eight-goal midfielder being available for Saturday’s visit to Field Mill.
He said: ‘Gareth got a really bad knock on his ankle in the first-half, it was a bit of a naughty tackle and he had to come off at half-time.
‘He is now being assessed. I don’t think he is a doubt for the weekend, but it was a nasty challenge.
‘The lad ripped through his sock and his ankle was really, really swollen at half-time so we had to withdraw him.
‘Initial thoughts are because it is just a bang, albeit a heavy one, he should be okay for Mansfield.’
However, Brian Murphy is not expected to return from his calf problem for at least two weeks.
The keeper has not featured since suffering concussion in the FA Cup replay victory over Ipswich in January.
While ruled out, he damaged his calf at the training ground, extending his first-team absence.
He has so far missed the Blues’ last 12 matches.
Foster added: ‘Murphy is still recovering from a significant calf strain.
‘I am not sure where he is on his rehabilitation at the moment, I would imagine he is somewhere in the region of being a few weeks.
‘It was a pretty significant tear to his calf, I would say at this stage he is two weeks away.’