Edinburgh and Scotland centre Nick de Luca received a 13-week ban for a dangerous tackle on Wednesday, a suspension which if upheld should see him ruled out until the end of the season.
The ban was imposed by a disciplinary hearing after de Luca was sent off during Edinburgh's 24-7 loss away to Welsh regional side the Ospreys in the Celtic League on Friday.
De Luca was shown a red card for a tip-tackle, now regarded as one of rugby's most dangerous offences by officials, on Ospreys winger Tom Grabham at the Liberty Stadium.
The 29-year-old de Luca, who won the last of his 38 caps in Scotland's shock defeat by Tonga in Aberdeen in November and has not yet featured in the ongoing Six Nations, has the right of appeal.
De Luca was playing for just the second time Friday following his return from surgery on a fractured eye socket suffered in training in January, an injury which was set to sideline him from the Six Nations completely.
Explaining how de Luca had been banned for 13 weeks, a statement from the league said: "Nick de Luca, the Edinburgh centre, appeared today before an independent RaboDirect Pro12 (Celtic League) disciplinary committee comprising Michael Coghlan, Dr Barry O'Driscoll and David Hurley (all from Ireland), following the red card issued by the referee for a tip tackle contrary to Law 10.4(j) during the Ospreys and Edinburgh match on Friday 22 February.
"Having considered all of the evidence presented, including the video of the incident, the disciplinary committee considered the incident to be at the top end level for this type of offence, which has a range of suspensions from 12 to 52 weeks and having taken into account aggravating and mitigating factors, decided that a suspension of 13 weeks was appropriate.
"The suspension concludes at midnight on Sunday 26 May 2013. The player has a right of appeal."
In de Luca's absence Scotland, beaten in their opener by England, have won back-to-back Six Nations matches for the first time since 2001 following victories over Italy and Ireland.
They are now third in the standings, level on points with second-placed Wales -- their opponents in the fourth round of the Championship at Murrayfield on March 9.