Tareiq Holmes-Dennis is pinpointed for a March or April return.
However, Kenny Jackett does not expect the injured left-back to feature again for Pompey this season.
Holmes-Dennis damaged his knee on the opening day of the League One campaign against Rotherham.
Such was the severity of the injury, Pompey were forced to dip into the loan market once more to find a replacement.
That prompted the deadline-day signing of Damien McCrory, who has since impressed in two appearances.
Holmes-Dennis is now undergoing rehabilitation at parent club Huddersfield, although remains contracted to Fratton Park for the remainder of the season through the terms of his loan deal.
Statistically on the big knee injuries, the dangers of a recurrence are between 8 and 10 months. That is a massive percentage, so you have to respect that statKenny Jackett
However, Jackett does not anticipate seeing him in action for the Blues before the campaign ends.
Pompey’s boss said: ‘I think it will be difficult for Tareiq to play again this season – if he does it will be a bonus for us.
‘He really has to get this injury right, so maybe March or April he might be okay, we shall see.
‘Tareiq remains on loan with us and it’s one of those we will have to see what the back end of the season brings but he won’t be rushed.
‘You have to be very careful when you come back from those type of injuries.
‘Statistically on the big knee injuries, the dangers of a recurrence are between eight and 10 months.
‘That is a massive percentage, so you have to respect that stat.
‘While they may be training well and saying “yes, I’m fit” and while you as a club might need them, you have to still respect that.’
McCrory is on loan at Pompey from Burton initially until January.