Northampton midfielder John-Joe O'Toole needs surgery on a groin injury in a blow to new boss Jimmy Floyd Hasselbaink.
The 28-year-old has not played since a pre-season run out in July and faces a couple more weeks on the sidelines, meaning he will sit out Tuesday's visit of Portsmouth.
Aaron Phillips (thigh), Sam Foley (knee) and Sam Hoskins (knee) are all out having missed Saturday's 1-0 win over Doncaster.
It gave Hasselbaink the perfect start to his reign at Sixfields and handed the Cobblers their first win of the season - and first since March.
Ollie Hawkins will be absent for Portsmouth following his clash of heads with AFC Wimbledon's Callum Kennedy on Saturday.
Hawkins, who also suffered a head injury on his Pompey debut against Rotherham in the previous game, required six stitches in a wound and may not even be ready to return when Fleetwood visit Fratton Park at the weekend.
His absence could open the door for Conor Chaplin following his goal-scoring appearance from the bench against the Dons.
Meanwhile, defender Jack Whatmough could be out of action for up to six months after undergoing knee surgery.