Bolton midfielder Mark Davies has been ruled out of action for up to 10 months after damaging the anterior cruciate ligament in his left knee.
Davies sustained the injury when twisting awkwardly during Tuesday night's 1-0 win over Peterborough in the Championship.
The setback comes just days after the 25-year-old had agreed a new contract with the Reebok Stadium club until 2017.
The former Wolves man recently returned from a shoulder injury that had kept him out for seven weeks.
Bolton manager Dougie Freedman said: "It's a blow for Mark, but he'll come back stronger.
"I believe Chris Eagles can now step up and deliver in that role."