O'Shea boost for Blues
Chesterfield will be without Drew Talbot for the visit of Northampton.
Talbot suffered a broken toe against Wycombe last weekend and the versatile 26-year-old is expected to be out for around a month.
Manager Paul Cook's squad has been hit by a virus but the Liverpudlian has stopped short of naming those players affected.
Brennan Dickenson has returned to Brighton following the end of his loan spell while fellow forwards Luis Boa Morte and Craig Westcarr left the club this week.
However, Cook managed to sign MK Dons winger Jay O'Shea on a permanent deal in time for Saturday's game.
O'Shea played the final match of his loan spell at Wycombe, scoring the Spireites' goal in their 2-1 defeat at Adams Park, but the Irishman will now remain at the Proact Stadium until June 2014.
Northampton boss Aidy Boothroyd is expected to name an unchanged side.
The Cobblers reported no fresh problems following the 3-1 home win over Fleetwood last weekend.
Jake Robinson sustained a large gash to a shin against the Cod Army but the forward has trained all week and will feature on Saturday.
Long-term absentee David Artell is back in full training, along with fellow defender John Johnson, following an Achilles injury.
Boothroyd wants to give both players a run-out in a practice match before committing them to first-team action, though.
Northampton will take extra caution over the return of Johnson after he suffered a setback on his playing return in November. The right-back has since undergone a second knee operation.