Pompey will once again be without Carl Dickinson.
The left-back is sidelined with a knee injury which requires surgery.
That keeps the door open for Hermann Hreidarsson to continue in the side following an impressive display at QPR.
Steve Cotterill must decide whether to operate with two strikers against Derby.
A reshuffle could mean a recall for Kanu.
Joel Ward, who looked tired in midweek, may be the player who drops to the bench.
Cotterill said: ‘Nothing has changed in my mind to the last time we played Derby.
‘I think Nigel (Clough) has done a fantastic job there.
‘It’s very difficult when you try to get hold of a club in a transitional period, whether it’s the squad or the finances – as I know only too well.
‘While Derby’s problems were not as severe as ours, I have sympathy with him trying to change his squad around.
‘Nigel has done a very good job and, hopefully, that will continue for him – on Sunday or Monday, though.’
Derby are still without Dean Leacock for tomorrow’s clash.
The central defender is sitting out the second game of a two-match ban so Miles Addison will continue to partner Shaun Barker.
Veteran midfielder Robbie Savage may have to settle for a place on the bench again, having been dropped for the midweek defeat against Ipswich.
Russell Anderson (calf) continues to be sidelined. Jake Buxton could be on the bench as he maintains his recovery from a long-term injury.
Rams midfielder Ben Davies said: ‘Our fans protested in the week and you can understand their frustrations.
‘We want to be up there, in and around the play-offs, just like they do and rightly so. This is a massive club.
‘We’ve just got to keep plugging away and battling.
‘Confidence comes with winning games, and as soon as we start winning, the better the lads will be.
‘Hopefully, the result will go for us tomorrow.
‘Portsmouth will be a tough game but it’s a great chance for us to bounce back and starting moving forward again.’