Tyrone boss Mickey Harte has revealed that forward Stephen O'Neill requires knee surgery which could keep him out of action for up to six months.
The Clan na Gael clubman, a former All-Star, will miss most of the National League campaign.
O'Neill needs the operation to sort out a knee tendonitis condition which has troubled him for some time.
Harte's priority is to have O'Neill back in action for the Ulster and All-Ireland Championships.
Tyrone skipper Brian Dooher is expected to return to training in six to eight weeks after having an operation for a hernia problem.
Mickey McGee is recovering well after shoulder surgery and should be all right for the league programme which starts in February.
