AFC Wimbledon centre-back Andy Frampton will be out for eight weeks after sustaining a broken ankle in training.
The 34-year-old scored four goals in 33 appearances for the Dons last season.
"It was a freak training ground incident and no one was to blame for it," Wimbledon boss Neal Ardley told the club website.
"We are obviously gutted and disappointed after hearing the X-ray result. We will be looking to bring someone else in."