Ulster's Iain Henderson could be facing up to six months out of action after a serious hamstring tear during last Friday's Pro12 win over Edinburgh.

The province's Director of Rugby, Les Kiss has revealed that the second-row will have to visit a surgeon this week to establish the extent of the problem, but the 23-year-old is almost certain to miss Ireland's Six Nations title defence.

"Iain's type of injury has historically been up to six months," said Kiss.

"At this stage it doesn't look good in terms of the Six Nations."