The French star tucked home a last-minute winner - his sixth goal in six games - in the 2-1 Premiership victory at the Walkers Stadium.
But Fredi was left in a heap after Muzzy Izzet's tackle in injury time and was stretchered off. He later limped away on crutches.
Caretaker boss David said afterwards: "Fredi is very sore at the moment but he'll have X-rays and scans tomorrow. It's an ankle problem but hopefully it won't be as bad as it looked."
David Pleat reported that Fredi Kanoute was 'very sore' after our match winner was stretchered off at Leicester City.