Pompey are waiting to learn the extent of Ronan Curtis’ injury sustained against Peterborough.
The in-form winger conjured up two assists to inspire the Blues to a 2-1 victory at London Road on Saturday.
However, he limped off the field in the 90th minute, to be replaced by Brandon Haunstrup.
Curtis had been caught by Marcus Maddison and then Jamie Walker during a surge upfield from his own half, the latter earning a booking for his tackle.
Assistant boss Joe Gallen believes the Irishman suffered a knock to the top of his left foot.
Now Pompey’s medical staff are assessing the Irishman to discover the full damage.
Gallen said: ‘We will have to wait and see, I didn’t think it was a great tackle on him at the time from Maddison.
‘It will be tough to calm him down and not let him go out there and train tomorrow or Tuesday!
‘Afterwards he had some ice on it and was limping around, I don’t know the damage, we’ll see.
‘He got a good bang on the top of his left foot, which is painful.
‘I don’t know the damage, I am sure he’s going to be okay, let’s see.
‘His enthusiasm level is infectious, he is confident and he is bubbly, he is a force of nature,
‘Ronan is very, very confident, has infectious personality and is very determined. The crowd have really taken to him, he's got a big heart – and what is there not to like on the football pitch?’