Simon Ferry is set to be ruled out for the remainder of Pompey’s season.
The midfielder lasted only 38 minutes of Saturday’s impressive 4-1 hammering of Dagenham & Redbridge, before being forced off through injury.
As feared, it’s a recurrence of the back problem which had recently kept him out for 14 matches.
Ferry received injections as a short-term solution ahead of planned extensive treatment in the summer to eradicate the on-going concern.
The Blues’ medical staff are currently assessing the extent of this latest setback, but the Scot is not expected to feature in the remaining four matches.
Caretaker boss Andy Awford said: ‘Simon pulled up after about 20 minutes and then shouted he was okay and it niggled again.
‘It is always a worry with him that we have got to manage him.
‘Should I have played him in such a big game?
‘If we were safe I would have wrapped him up in cotton wool and looked after him a bit, but he is such an important player for us and you see the value of him when he is on the pitch.
‘Hopefully we have caught it early enough so it is not back to square one with him, we will see.
‘What I will say is we have lads ready and willing to come in and do a job.’
Rhys McCabe came off the bench to replace Ferry at Victoria Road and weighed in with two assists.
It was his cross-field pass which fed Michael Drennan for his stunning second goal in the 57th minute.
Then three minutes from time the loanee from Sheffield Wednesday clipped the ball back from the byline for Jed Wallace to complete the 4-1 scoreline.