The on-loan Manchester City star damaged his knee against Burnley at the weekend and has been ruled out of the Crewe game on Saturday, the home game against Norwich and then the Easter Monday clash at Brighton.
But Sturrock is still hopeful that he will be able to keep the player on loan until the end of the season because Richard Wood and Drissa Diallo have not yet proven their fitness.
If City do allow the player to stay at Hillsborough, it is most likely he will only be available for the Reading and Derby games at the end of the current campaign.
Sturrock is still in negotiations with Liverpool to make sure Scott Carson stays at the club until the Derby game - currently as it stands, the England Under-21 keeper's loan spell ends after the trip to Gresty Road.