Tyrone's star attacker Stephen O'Neill could miss the rest of the NFL campaign with a knee injury picked up in the recent Croke Park win over Dublin. Former player of the year O'Neill sat out Sunday's bruising league defeat to Kerry in Omagh and has already been ruled out of forthcoming league games against Galway, Westmeath, Donegal and Derry. "Stephen did some damage to the knee in the Dublin game and it may have been a case that the full extent of the injury wasn't really appreciated after that game," said Tyrone boss Mickey Hart.