Queen of the South have confirmed midfielder Steve Tosh broke his left leg in the Co-operative Insurance Cup third-round defeat to Rangers.
Tosh landed awkwardly as he made a tackle with less than half-an-hour remaining of Wednesday night's 2-1 defeat at Palmerston Park.
The 36-year-old will find out later in the week if he will need an operation.
Queens boss Gordon Chisholm told BBC Scotland: "I'm absolutely devastated for Stevie. We'll need to wait to see how long he'll be on the sidelines."
Former Aberdeen midfielder Tosh left the field on a stretcher after his leg twisted underneath him as he attempted a tackle.
As well as the fracture to his fibula, Tosh also suffered ligament damage.
Tosh has been a key player in the Queen of the South team since joining the Irn-Bru First Division club from Gretna in January 2007.