Pompey are sweating on the fitness of Liam Lawrence for the trip to Doncaster.
The midfielder has been receiving intensive treatment all week on the calf injury which kept him out of action for the Republic of Ireland.
Jonathan Hogg has also not trained, although is expected to feature.
Definitely out is Aaron Mokoena, who is back in South Africa awaiting his work permit.
That has put Ricardo Rocha in the frame to replace him as Greg Halford’s partner in the heart of the Blues defence.
Blues defender Hermann Hreidarsson said: ‘They’re a good side, we know that – we know what they can do.
‘We had a good game against them earlier this season – they went 2-0 up and I thought we showed good spirit to come back and draw level.
‘Unfortunately, it wasn’t enough on the day and they went on to win.
‘But we showed great character and I know that we can use that.
‘I know it’s a cliché when players talk about spirit but it’s real here.
‘The way we work together gives us great confidence for the rest of the season.’
Doncaster are keeping their fingers crossed some of their walking wounded will return.
No fewer than 12 players were out injured for the defeat at Millwall last weekend.
James Coppinger (ankle), Matt Kilgallon (hamstring) and Neil Sullivan (shin) are all expected to come back against Pompey.
But eight-goal James Hayter (calf) leads the lengthy list of those still missing.
Others include Shelton Martis, Wayne Thomas, Adam Lockwood, Simon Gillett and Joseph Mills.
Rovers assistant manager Richard O’Kelly said: ‘Portsmouth are very dangerous from set-pieces.
‘They’ve also got players, such as Kitson, Nugent, Kanu and Lawrence, who have all played in the Premier League, so have an awful lot of quality.
‘One of the things about Portsmouth is that they go for 90 minutes plus.
‘They were very resilient and at their place, came back to level at 2-2 and looked at one stage as though they might win it.
‘It is in their nature; it is in manager Steve Cotterill’s nature. They have an up-and-at-’em attitude.’