Carlo Ancelotti's side recouped around half of the £86m they paid for Gareth Bale when they allowed Ozil to leave for London on deadline day, but his departure surprised Bernabeu fans and team-mates alike.
The playmaker could now make his debut at Sunderland on Saturday and Cazorla is sure his arrival can help the Gunners mount a sustained title challenge.
"I am very happy that Ozil is here," Cazorla was quoted as telling Spanish newspaper Marca.
"He is a spectacular player and we are very lucky that we are going to learn alongside him.
"I don't understand that (why Real Madrid sold him), (because) he is a unique player.
"You will have to ask the club for reasons why they sold them, but at the same time he didn't think he was getting the opportunities he deserved and luckily he has come to us.
"He is an important player and he is going to be very good for the team and
the way we play. I hope he can help us fight against the big teams in the