Portsmouth will be without defender Adam Webster when they welcome Northampton to Fratton Park.
The teenager was sent off for two bookings during the first half of Saturday's 2-1 win over Cambridge and serves a one-match ban.
Webster's absence could see a return to the side for captain Ben Chorley, who missed out on a place in the squad at the weekend.
Former Brighton goalkeeper Peter Brezovan has arrived on non-contract terms as cover for Michael Poke, who has an Achilles injury and joins Patrick Agyemang (hamstring), Danny East (groin), Tom Craddock and Wes Fogden (both knee) on the sidelines.
Darren Carter could miss the Cobblers' trip south after suffering a hamstring injury.
The midfielder limped out of Saturday's 1-1 draw at York and has been troubled by the problem already this season.
He missed the League Cup win over Wolves last week and only lasted an hour at Bootham Crescent.
Chris Hackett is also a doubt with an Achilles problem while Kelvin Langmead (Achilles) and Lewis Hornby (tendonitis) are both still long-term absentees.