Kenny Jackett has admitted his relief after Damien McCrory's injury was not as serious as first feared.
The left-back twisted his knee during the first half of Saturday’s win against Fleetwood.
A scan has revealed the injury is not as bad as initially felt, with McCrory anticipated to return to training next week.
However, he is ruled out of Saturday's trip to Scunthorpe, opening the door for Dion Donohue to retain his place following last weekend's substitute appearance.
Jackett said: ‘It doesn’t seem as if there is any structural damage to it.
‘The knee is still sore but the physio’s assessment at the moment is he won’t be fit for the weekend, but hopefully can train next week.
‘You never know how bad these things are. You twist your knee in a block tackle and don’t want it to be anything bad. We are looking to get him over it pretty quickly.
‘We are not blessed with loads of defenders and Damien is an experienced one who’s had a good start to his Portsmouth career.’