Gunners boss Arsene Wenger was roundly criticised for a lack of summer transfer activity at Emirates Stadium, but pulled off one of the deals of the window on deadline day.
He did have to part with over £40million to lure Ozil away from Real Madrid, but the Germany international's arrival in north London has captured the imagination.
Mertesacker, who has played alongside Ozil for club and country, is convinced that Wenger will get the best out of the 24-year-old and make him a Premier League success story.
After helping Germany to a 3-0 victory over Austria on Friday, the towering centre-half said: "I know him quite well. We spent two years together at Werder Bremen so I think that Arsene Wenger will get the best out of him.
"I think he will fit in. He suits us and we're really looking forward to playing with him and to be his team-mate."
Mertesacker also claims that he knew Wenger would make a statement signing at some stage, with Arsenal having worked hard behind the scenes to get the right deals in place.
He added: "We were patient all the time on the transfer market. Mr Wenger said always that he was on the market but nothing happened.
"I could feel that something happened at the end of the transfer window. So I really appreciate that transfer."