Ulster forward Nick Williams has been suspended for eight weeks for striking opponent Rhys Patchell during the Pro12 match against Cardiff Blues.
New Zealander Williams was sin-binned in the early stages of Friday's match and was later cited over the incident.
He appeared at a disciplinary hearing on Wednesday and was told the matter was at the higher end of the scale.
The committee ruled that, because Ulster have four matches left, Williams will not play again until 1 September.
Williams got the yellow card after his forearm connected with Blues full-back Patchell's head.
Patchell needed treatment for almost 10 minutes before being taken from the pitch on a motorised stretcher.
He returned home on Saturday after spending the night at a Belfast hospital undergoing concussion tests.
The Disciplinary Committee was chaired by Roger Morris (Wales) and also included Rhian Williams (Wales) and John Doubleday (England).
Their statement read: "Having viewed footage of the incident and listened to representations made by and on behalf of the player, the committee found that the incident was at the top end of the World Rugby sanctions for this type of offence, meriting a 16-week starting point.
"In the absence of any aggravating factors and in light of several mitigating factors, including the player's exemplary previous playing record, the committee applied an eight-week reduction from the entry point."