Ozil has been training with his new team-mates for the first time and could make his debut this weekend when the Gunners return to Premier League action with a trip to Sunderland.
I played against him with the national team and he was the man of the match. It's not good to have him against you
And the French defender praised the Club for showing their desire by bringing in a "world-class player".
"I'm very happy. He's a quality player and we need players like him to come to Arsenal, hopefully he can make the difference offensively," Sagna told Arsenal Player.
"Technically he is a world-class player. He can assist many goals, he did it in the past with Real Madrid and Werder Bremen so I think he's going to do it with us.
"I played against him with the national team and he was the man of the match. It's not good to have him against you."
Sagna also believes Ozil's arrival can give the squad a vital boost as they enter a busy schedule with the Champions League starting on Wednesday.
"Now we are ready to go even further because we started the season quite well, except for the first game of the season. We've done well until now so I'm looking forward to playing with him."Copyright 2016 The Arsenal Football Club plc. Permission to use quotations from this article is granted subject to appropriate credit being given to www.arsenal.com as the source