Adam Webster is set to undergo an operation on his injured knee.
The Pompey defender faces a stint on the sidelines after damaging cartilage against Northampton Town last week.
It’s a blow for the 19-year-old, who has made five appearances for Andy Awford’s Blues outfit this season.
Awford said: ‘Webbo’s had a scan and has some meniscus damage in his knee.
‘There’s a bit there so they are going to open him up this week and the surgeon is going to have a look at him.
‘He does need an operation.
‘Fortunately it’s not one of the big ligaments.
‘It’s good news to rule that out. That’s good news for him.
‘There is damage, though, so they need to do it.
‘They will know more when they go back in.
‘He’s had the scan and it’s shown cartilage damage, so he needs to sort it out.
‘He’s been out and came back in the other night but it’s a big blow for him.
‘We will wrap him up and get him back out there as soon as we can.’
Meanwhile, there is better news for Ben Chorley, who has returned to training after a calf injury.
Jack Whatmough is still waiting for the all-clear to return as he recovers from a hamstring problem.
Danny East (ankle), Wes Fogden (knee) and Tom Craddock (knee) remain sidelined for the Blues.
Awford said: ‘Jack hasn’t trained.
‘He has an issue with his hamstring which is back related.
‘He’s managing it but we have no timeframe on it.
‘Ben has trained and is back now.
‘So the only injuries we have are Whatmough, Webster and the long-term three.’