The 21 year old was on his second spell with Posh after spending time there last season; he recently returned to London Road for a second stint but has only lasted a month before injury.
The player is expected to be out of action for six weeks.
Posh boss Darren Ferguson told the club's official website: "It's a blow for Scott and a blow for the team, but we have him on loan until the end of the season so he could still come back."
