Pompey have been dealt a double injury blow over Matt Tubbs and Gary Roberts.
The pair are facing at least four weeks on the sidelines over their ankle injuries.
Roberts has been out since the Stevenage game last month, while Tubbs missed the FA Cup win over Macclesfield last weekend.
Pompey boss, Paul Cook, said: ‘It was great credit Gary played on with that injury.
‘But, as our supporters saw, he was gradually getting worse by the game.
‘Matt Tubbs is now out for a month with a similar injury.
‘It’s going to be four weeks-plus with both of them.
‘There is a likelihood they could need an operation.
‘There is no guarantee they’ll be back after that.
‘But we have to ride these difficulties and keep going.’