Even a draw will not be enough for Michael Appleton's men, who require all three points to keep their status as a Championship side intact. That may not be enough though if Bristol City win their encounter with West Ham United.
However, Dave Kitson is expected to return to the starting lineup following a spell on the bench.
Pompey will be able to take heart from the fact that they have lost just once in their last nine home fixtures against Dougie Freedman's side.
Portsmouth: Ashdown; Ward, Rocha, Pearce, Rekik; Halford, Norris, Allan, Harris; Kitson, Futacs
Palace: Speroni; Clyne, McCarthy, Moxey, McShane; Garvan, O'Keefe, Ambrose, Scannell; Zaha, Martin
Sports Mole says: 2-0