Brett Pitman believes he will be fit to face Plymouth on Saturday.
But Pompey boss Kenny Jackett insists he won’t be taking any risks with his captain.
He picked up that setback in last Saturday’s 1-0 victory against Southend.
After previously being ruled out of the clash against the Pilgrims, Pitman feels he will be back in time to spearhead the Blues’ attack.
But Jackett is rating Pompey’s top scorer as doubtful for the game.
The Blues boss said: ‘The positive is it is Thursday and he is saying he will be fit – which shows his attitude.
‘We won’t take any risks with a hamstring. It will be a decision between now and Saturday morning as to whether he is fit.
‘I will be rating him as doubtful. It will be a doubt that he plays but we will see.
‘After that, as with Tuesday, we have to work out a way of getting the goals and being a goalscoring threat without him.’