The 21-year-old, who arrived on an emergency loan until the end of the season
, was stretchered off just 15 minutes into Saturday's 3-3 draw
with Derby County.
Thorpe has since had a scan and appears to have sustained ligament damage to his right ankle and will remain with the Red Devils for further treatment for the foreseeable future.
There is no clear indication on a return date for the centre-back but Lee Clark will continue to be updated throughout the youngster's treatment programme.
Following the news on Saturday, Clark said
: “We’re devastated for him. He’s a terrific kid and we were absolutely delighted to get someone of his quality. Manchester United rate him so highly and he’s been a brilliant lad."