It is bad news for Reds boss Billy Davies who is already without strikers Dexter Blackstock and Robert Earnshaw.
"It is a massive blow to lose Nathan for a month," said Davies. "To lose the pace of Tyson and the goal scoring of Tyson, along with Blackstock and Earnshaw, means we have got key players missing from the squad.
"As I have said before, top teams can't afford to lose important players. The Bristol City game on Saturday might come too early for Dexter Blackstock, while Earnshaw is probably looking at Middlesbrough after the international break."