Ellis Harrison is likely to miss the rest of the season with a knee injury and has now been joined on the treatment table by Jordy Hiwula.
It means that the fit-again John Marquis is currently the only available senior striker at Pompey’s disposal.
But he is set to miss the next three games after being shown a straight red card in a 2-1 victory at Shrewsbury.
Referee Benjamin Speedie made the decision following a challenge on substitute Harry Chapman midway through the second half.
But Marquis – who had earlier netted his 16th goal of the season – hopes that the suspension will be overturned.
He said: “I immediately felt that it was a good tackle. I went in one-footed and wasn’t high off the ground.
“There are different ways to tackle in the game, but I’ve gone in there and have actually won the ball.
"I immediately felt that it was a good tackle. I went in one-footed and wasn’t high off the ground."
“Just because you go to ground, it doesn’t mean that it’s a red card. I was shocked with the decision to be honest.
“We’ll have to look back on it and see if there’s a chance to appeal the red card, but I think that there is.”
Marquis tapped home to double Pompey’s advantage after Lee Brown had sent a dangerous Ben Close cross towards the bottom corner.
He said: “I don’t know what Lee’s on about saying his shot was going in! I was just there to make sure and it’s always pleasing to score.
“I’ve been out for a little while and wasn’t 100 per cent, but with the problems we’ve got in forward areas, I wanted to play.
“You can see the progress we’re making and now there’s a chance to get another good week on the training ground ahead of the Rochdale game.”