Saracens back Charlie Watson has been handed a four-week ban for booting Saints centre Andy Symons in the head during last Sunday's game at Franklin's Gardens.
Watson was red carded for the incident, while referee Craig Maxwell-Keys yellow carded Symons for holding his opponent's leg in the build-up.
Watson attended a disciplinary hearing on Tuesday night and was charged with kicking.
He was given a four-week suspension by the panel and is free to play from November 8.
Panel chair Richard Whittam QC said: “The panel accepted that this was an act of frustration by the player in trying to release his leg from being held by Northampton Saints 12.
“Contact was clearly made with the face of the Northampton player but the action was petulant rather than with any intent to cause injury.
"In this instance no injury was suffered and the Northampton player continued in the match after returning from the yellow card.
“The sanction table mandates a mid-range entry point where there is contact with the head, in this case that entry point is eight weeks. The panel found no reason to go above that.
“The player accepted the charge, has no previous record and expressed remorse for his actions.
"In the circumstances the panel felt able to give the player the maximum mitigation of 50 per cent.
“The panel note that whilst the yellow card awarded to Northampton Saints 12 was not brought before them for consideration, it is disappointing to see actions of this nature in the professional game.”