The French international received a ridiculous red-card yesterday.
To be fair he was angered by what was a needless nudge by the defender, which could have seen him seriously injured if he crashed into the goalkeeper Rob Green at high velocity.
But his reaction was ludicrous. He charged at Onouha and put his head into the forehead of the defender, who obviously fell to the floor and got Giroud sent for an early bath.
With Arsenal cruising at 2-0 Giroud's actions were reckless and irresponsible and he gave his team-mates a hard time for the remainder of the game.
The reaction of Arsene Wenger though, who was visibly irritated as his star striker left the field of play, shows how annoyed he is at the fact Giroud will now miss three games for Arsenal.
The games he does miss are also fixtures they would have liked him to be available for.
They will fancy their chances at home against Hull City on the 4th January without him. However they have tough away games against West Ham United and Southampton up next, with the high-flying sides ready to truly test the Arsenal.
Giroud's absence will give Danny Welbeck the opportunity to shine through the middle, but Wenger would have liked to have the Frenchman as an option.