The Ulster star was hoping to play his part in the tournament in 2017 but suffered an injury during Ireland's win over Australia last time out.
Scans have since shown kidney damage and Ulster have confirmed he is expected to miss around three months of action.
That lay-off will see him miss at least three of Ireland's matches - with Scotland, Italy and France up first.
He will hope to take on Wales and England in March while his injury will also see him miss key games for Ulster including European Rugby Champions Cup games against Clermont Auvergne.
Ulster have also lost Andrew Trimble for the next two weeks after he suffered a foot injury against the Wallabies.
The winger was brought off after 30 minutes and a tendon injury will keep him out until the middle of December.