Saracens' Schalk Brits has been suspended for three weeks after pleading guilty to punching Gloucester's Nick Wood.
The talented hooker was sent off by referee Craig Maxwell-Keys for the incident during the first half of last week's Aviva Premiership fixture between Saracens and Gloucester, and the charge against him was heard on Tuesday evening.
He will be available for selection again from March 15.
Brits, 34, punched Wood, leaving the prop concussed and unable to continue, after reacting angrily to being awkwardly pushed over.
He was defended by Saracens' director of rugby Mark McCall, who after the match told reporters: "There are no complaints about the ref's decision, it was a red card.
"But if you look at the incident, Schalk's knee was trapped underneath and I think he's frightened and trying to get him off him as quickly as he can. He did his ACL [anterior cruciate ligament] last September and there was an element of fear involved."
Saracens eventually won 25-12 and retained a four-point lead over Exeter at the top of the Premiership.