The Swiss midfielder joined the Gunners from Borussia Monchengladbach in the summer transfer window and admits it was a nerve-wracking experience meeting the Frenchman for the first time.
Speaking to Appenzeller Zeitung, the 23-year-old said: "I have to admit, in the first few days there was a certain undeniable nervousness.
"[The first time we met?] Pure excitement!
"I was really very nervous. He has an incredible way, an insane charisma.
"You look at him and know: 'Wow, this man has achieved and experienced so much.' The respect for him is enormous."