Arnold's three-week tackle
Arnold faced a disciplinary hearing and has been banned for three weeks.
Munster, who held a 17-0 lead at half-time, saw Irish rivals Ulster to come back and clinch a bonus-point (24-17) win in their Pro14 Round 12 encounter this past Monday.
Munster had two men carded in the game – replacement Fineen Wycherley was yellow-carded in the 54th minute and centre Sam Arnold red-carded four minutes later.
The disciplinary panel convened in Neath to consider the red-card decision against the player.
The player was shown a red card by referee Sean Gallagher under Law 10.4 (e) – Dangerous Tackling.
The disciplinary panel – comprising of Roger Morris (Chairman), Nigel Williams and Owain Rhys James (all Wales) – concluded that the actions merited a mid-range entry point as a player must not tackle above the line of shoulders, an act of foul play which carries a six-week suspension.
The ban was reduced after full mitigation of 50 percent was applied – having taken into account the player's conduct throughout the hearing and his previously clean disciplinary record.
As a result, the player has been banned for a period of three weeks.
He is free to play from Monday, January 22.
It means he will miss the crucial Pro14 Round 13 encounter with Connacht this week, as well as the next two rounds of European action – against Racing in Paris on Sunday, January 14, and against Castres on Sunday, January 21.
The player was reminded of his right to appeal.
