Curtis Main is a doubt for Pompey’s trip to Accrington Stanley.
And that could open the door for a first start of the season for Conor Chaplin.
Main was forced off in the 25th minute of Saturday’s 4-2 victory over Wycombe with a head injury.
The striker sustained a cut above his eye following an aerial challenge with Chairboys defender Aaron Pierre.
His replacement, Chaplin, netted a stunning goal in an outstanding all-round performance.
The injury is ill-timed for Main, who netted twice in his previous Blues outing against Crawley.
Pompey’s medical staff are continuing to assess the 24-year-old’s injury.
On a plus side, no concussion was caused by the hefty clash of heads inside Wycombe’s penalty area.
Although, first-team coach Ian Foster regards Main as 50-50 to be available for Saturday’s Crown Ground visit.
Foster said: ‘It’s a nasty cut which has come down into his eye – and a difficult one to bandage up because it just comes below the eyebrow.
‘Curtis has been in, it is obviously very sore and swollen and we’ll see how he is towards the end of the week.
‘He didn’t lose consciousness but has a banging headache. There’s no concussion, it’s just a nasty gash.
‘Fingers crossed, he will be okay for Accrington – although I wouldn’t like to say at the minute.
‘He is probably 50-50 right now.’
The visit of Wycombe represented Main’s seventh appearance since moving from Doncaster in the summer for an undisclosed fee.
He has so far scored three goals for Pompey.