Thorne is yet to make his debut since moving last month.
"George has been brought in as an extra midfield player to give us cover but the way John Eustace, Craig Bryson, Will Hughes and Jeff Hendrick have done, George is having to be patient," Simpson told the Derby Telegraph.
"We have 16 games to go and there is every chance he is going to get an opportunity.
"We are going to pick up knocks and possibly suspensions. John Eustace is on nine bookings.
"Something will happen and then, hopefully, George will slot straight into the position he has been asked to play."