The French star, 22, sealed a £5million move to The Emirates just 10 minutes before the transfer deadline.
"I know it will be tough to make it at Arsenal as well.
"I have no guarantee from Arsene Wenger I will play all the time but I am sure that it will be OK.
"I know I will play big matches in the league and even in the Champions League."
And he added: "I knew for some time Mr Wenger was interested in me.
"He watched me with Chelsea and the France national team. They were my first choice and my first priority.