Pompey remain unable to plot a timescale for Curtis Main’s return to football.
The striker has frustratingly been sidelined through injury for the past 13 weeks.
It has been 13 weeks, the kid is not playing and it’s been tough on him, especially at a time when we’ve been short on strikers if you look at the different permutationsPaul Cook
Initially an abdominal problem, it has now developed into a knee issue, extending his spell in the treatment room.
The summer recruit from Doncaster Rovers had netted five times in 14 matches before injury struck in late October.
Paul Cook is pursuing Eoin Doyle to bolster his centre-forward options, while Nicke Kabamba arrived last week.
In the meantime, Main continues to be assessed by doctors.
And the Blues boss admitted he is unsure when the 24-year-old will be able to resume training and aid Pompey’s promotion push.
Cook said: ‘It has been an ongoing process to get Curtis fit, he’s had a couple of issues which seem to be related.
‘Various doctors and specialists are obviously investigating, so fingers crossed we will get to the bottom of it.
‘But we have no idea when he’ll be back and that is the frustrating thing.
‘When you break your leg you have a timescale, but in this instance people are still investigating the injury. Surgeons are involved and they possibly want to go inside and have a look at it.
‘It has been 13 weeks, the kid is not playing and it’s been tough on him, especially at a time when we’ve been short on strikers if you look at the different permutations.
‘Considering we’ve had one of our strikers out for that length of time, I think the other lads have done really well just to keep it ticking along.
‘It’s a shame, he’s a positive player with a really good goals-per-minute record for this club.’
Main has endured a frustrating time since joining in July from Doncaster for an undisclosed fee.
Initially behind the rest of his team-mates in terms of fitness, the ex-Middlesbrough soon caught up.
He scored on his full Pompey debut in the 3-2 EFL Cup defeat at Coventry in August.
His first League Two goals arrived in a 3-0 victory over Crawley, yet the following match required stitches following a clash of heads against Wycombe.
Main then netted twice against Reading under-23s in the Checkatrade Trophy.
However, a substitute appearance against Notts County on October 22 represents his most recent outing.
Cook added: ‘We can’t do anything, we can’t pick someone who isn’t fit, it’s tough on anybody when they get an injury in any squad.
‘You have to feel for the kid. At the end of the day, no-one wants to be out for 13 weeks, not playing for a club like this where you can become a firm fans’ favourite by scoring the goals everyone wants.
‘People are working hard to get him fit – and Curtis is giving everything, too.’