The 20-year-old will face four-to-six weeks out of action after having the injury assessed on Monday.
It was originally feared that he had broken his ankle and Sharp had to be admitted to Scunthorpe General Hospital, however the striker returned to Glanford Park reporting no breakage.
Boss Brian Laws will now step his search for a loan striker as the Iron only have Andy Keogh, Tommy Johnson, Steve Torpey and Andy Parton as options.