Thurston faces a one-match ban after being charged by the match review committee for his fifth minute lifting tackle on New Zealand Warriors second rower Wairangi Koopu yesterday.
The Cowboys thumped the Warriors 49-12 at Dairy Farmers Stadium to book a clash against the Sea Eagles at Sydney Football Stadium, the winner of that match to play either Melbourne or Parramatta in the grand final on September 30.
But Thurston will have to beat his dangerous throw charge at the NRL judiciary to play on Saturday night, with an early guilty plea not enough to save him from suspension.
The grade one charge carries a 125-point penalty, but it is boosted to 150-points thanks to a 20 per cent loading from a striking charge in round three last year.
The early guilty plea would reduce that to a 112-point penalty, meaning a trip to NRL headquarters to fight the charge would be his only hope of taking on the Sea Eagles.