The 26-year old striker joined the Gunners in the summer after scoring 21 goals for La Paillade as they claimed the French Ligue 1 title last season.
Giroud started life quietly in North London but has hit back with five goals in his past five outings in all competitions and Girard hopes to quell his influence in the Champions League bout at the Emirates Stadium tomorrow night.
"Olivier worked very hard for us and we almost sculpted him into the player he is today. We made history at the club and had great times," said Girard whose side cannot progress to the knockout phase of the competition.
"Unfortunately for us, he is rediscovering his best form and starting to score goals, but we have tactics to try to stop him.
"We know how good he is, but there are also lots of attacking threats here at Arsenal."