Peterborough striker Callum Willock could be out for three weeks after suffering a calf strain during the 2-0 home defeat by Doncaster.
Willock has scored 11 goals for Posh this season
Posh boss Barry Fry confirmed: "He felt his calf pop and looks like he will be out of action for a lengthy time.
"It is a massive blow for us as we have two tricky games coming up against Sheffield Wednesday and Chesterfield.
"Hopefully Andy Clarke and Christopher Kanu will be back from flu," he added on the club's website.