Hull KR hooker John Boudebza has been banned for four games for the tackle that ended Castleford captain Michael Shenton's season.
Boudebza was charged with a Grade B offence for the tackle on Shenton in Sunday's 16-16 draw at the KC Lightstream Stadium, with a two-game ban normally the maximum sanction.
But the Rugby Football League has used discretionary powers to amend the grading due to the aggravating factor of Shenton's season-ending anterior cruciate ligament injury.
Shenton is likely to undergo major surgery on his knee in the coming weeks, a huge loss for the Tigers to overcome from their first Super League match of 2016.
Hull KR have already announced they will appeal against the decision.
An RFL statement said: "The injury caused to Shenton was deemed an aggravating factor in this case.
"The tribunal has the discretion to step outside of the normal grading ranges in the following circumstance: If the compliance manager seeks a higher sanction in the light of specified aggravating factors and the tribunal agree that such factors mean a higher sanction should be imposed.
"An early guilty plea was available, however the match-review panel elected to withdraw this option as a serious injury was caused."
Boudebza, who pleaded not guilty, was also fined £300 and his suspension leaves Rovers without a specialised hooker - first-choice No 9 Shaun Lunt is sidelined after undergoing ankle surgery.