Derry have suffered a major injury blow ahead of the All-Ireland qualifier against Cavan after PJ McCloskey was ruled out for the rest of the year.
The midfielder sustained a cruciate knee ligament injury during Derry's 0-13 to 1-5 qualifier win over Down earlier this month.
McCloskey will have surgery after a scan revealed the extent of the injury.
The Oak Leafers will be chasing a place in the fourth round of the qualifiers when they take on Cavan on Saturday.
McCloskey missed the Ulster SFC quarter-final defeat by Down last month because of a hip injury.