The 26-year old had recently got back into the Bolton first team but was to suffer the fracture during Wanderers defeat to Manchester United at Old Trafford.
This latest blow marks a season of disappointment for the former Real Madrid ace, who has made infrequant appearances since his Free Transfer move from Real Valladolid in the summer.
Wanderers boss Sam Allardyce now has the afforementioned Gardner back to full fitness, and can also call upon the services of Florent Laville after he completed a two month loan spell with Coventry City.