The former Real Madrid striker criticised the German's inconsistency at the Emirates and says Manchester United should have signed Ross Barkley, not Marouane Fellaini
Arsene Wenger's side are perched at the top of the Premier League with 35 points after 16 games, though their form has wavered with consecutive defeats against Napoli and Manchester City.
Though he reserved praise for Olivier Giroud, the former Real Madrid attacker ripped into Ozil's performances since arriving in the Premier League and suggested Arsenal will drop off from the title race unless they sign another striker.
"There is little doubting that Wenger's men are now a well-oiled machine," Owen wrote on social networking site Sportlobster.
"The players all know their jobs inside out with Wenger rarely changing his system and against the lesser lights in the league I always fancy them to out-score their opponents.
"It is against the big boys where I think they could struggle as, in my opinion, they don't have the class of player to go toe-to-toe with the main title contenders.
"Despite people constantly telling me that Mesut Ozil is world class, his inconsistency means that we only see occasional glimpses of real quality.
"His odd good performance is usually followed by half a dozen poor ones and despite Giroud performing admirably, unless Wenger acquires a new striker to help share the load, they could just tail off the longer the season goes on."
Michael Owen fears David Moyes made a critical error in the summer by raiding his former club for Marouane Fellaini - who has failed to impress since his £27.5 million move - rather than England starlet Ross Barkley.
"Moyes would have expected an instant return on investment when buying Marouane Fellaini," the ex-Red Devils striker added.
"I rate him highly in a certain type of team but I’m not sure he is a Manchester United player.
"Moyes would have been better served by breaking the bank for another of Everton’s players. A team consisting of two of the best youngsters in the Premier League, Adnan Januzaj and Ross Barkley, would have immediately sent out the message that Moyes is building a team to last.
"[But] there is no doubt in my mind that David Moyes will be a huge success at Manchester United for years to come."