Matt Mills has returned to Manchester City having had his loan spell at Doncaster cut short by injury.
The young defender has impressed at the League One promotion hopefuls but a torn cartilage has ended his spell at Rovers.
Mills has been sidelined for six weeks and his loss will be a major blow to Doncaster, given he had started 17 games there having joined at the end of August.
Meanwhile, defender Sam Hird has joined Grimsby Town on a one-month loan deal.
The 20-year-old has made only three appearances for Sean O'Driscoll's side this season.