The 25-year-old makes an immediate return to his former club, where he was top scorer and won Ligue 1 last season, but insists he will put feelings aside and try to win the game
Giroud helped the French club to win their first ever league title last season and August's group stage draw means he will head back to the scene of his former glories a matter of months after leaving the club.
The 25-year-old, who is yet to score for the north London side, insists he will put his affection for la Paillade aside for 90 minutes, and help Arsenal get off to the best possible start in Group B.
"It is weird. It is something that destiny wants. I think it is a good thing. I have not had time to say goodbye to the fans of Montpellier and I think it will be very emotional for me," the striker told RMC Sport.
"I spent two beautiful seasons there, which will remain forever engraved in my memory. We'll see how it goes, but I will put the emotions aside for 90 minutes and do the job by winning this game."
Giroud also spoke of his first few performances at Arsenal, and despite not scoring, he believes that it won't be long before he opens his account for his new club.
He continued: "I found my first few weeks of integration successful. I feel very good at this club. It is true that there are occasions [of not scoring], so I do not worry about my first goal, it will come very quickly."