Nick Williams will miss the rest of the Pro12 campaign after a disciplinary committee found the Ulster back row guilty of striking Cardiff Blues' Rhys Patchell.
During Ulster's 37-16 win last Friday, Williams entered a maul and struck Patchell in the head with his right forearm. The Cardiff man was forced off on a stretcher.
Williams was sin-binned for the challenge at the time but has now been hit with an eight-match ban following a review.
The offence would normally have carried a 16-week suspension, but the disciplinary panel took into account Williams' previous record.
"In the absence of any aggravating factors and in light of several mitigating factors, including the player's exemplary previous playing record, the disciplinary committee applied an eight-week reduction from the entry point and suspended the player from playing for eight weeks," a Pro12 statement read.
"Taking into account the matches remaining this season, and two warm-up matches scheduled for the start of next season, Nick Williams is free to resume playing from Monday, September 1, 2015 and has the right of appeal."