No doubt. But despite the fact that the Gunners had almost a month to sign Vermaelen's replacement after he left, they signed no one.
Wenger often talks about how he will only purchase a player if he finds just the right man—someone who will add something the squad does not already have.
You know what the team does not have, Arsene? Four center-backs.
It is absolutely essential for any team to have a backup for each of its two starting central defenders if it wishes to make it through a grueling 60-game season without turning to patchwork measures.
All it takes is one injury or suspension in a squad with three center-backs and the club is down to its bare bones.
Arsenal were extraordinarily lucky to get away with such a setup last season, but their one natural backup was an excellent defender and Bacary Sagna was available if someone needed to play in an emergency. Luckily, they did not need to call upon their reserves very often.
They are even thinner this year. Sure, Mertesacker and Koscielny are lethal when played together, but the only option available to replace them is Calum Chambers. The Englishman is 19, not naturally a central defender (though he has impressed during his few cameos there) and Arsenal's only backup for Mathieu Debuchy.
At least if Sagna had to fill in last year, Carl Jenkinson could be called in to deputize for him at right-back. But if Laurent Koscielny's head injury is even somewhat serious, Arsenal will have utterly no defensive cover anywhere.
Does that sound insane? Of course. All it took was two injuries to stretch the Gunners to the limit and force Wenger to the verge of playing one player grossly out of position.
No other team deals with such a problem unless they are in dire financial straits and literally cannot afford to field a full team. Less prestigious sides can also get away with having less depth because they do not play as many games in as many competitions, nor do they travel outside England.
But Arsenal are one of the richest teams in the world, mounting a four-front challenge for silverware. The Premier League trophy is their main goal and is only attainable after a long slog.
They will have to maintain an elite level while jetting away for Champions League games against Europe's best and braving the spontaneity of the FA Cup and the League Cup, both knockout tournaments.
And they will have to do it all with the paranoia that accompanies risking your team's viability with every tackle and 50-50 challenge.
It just makes no sense to any rational person who watches football. Quite literally any center-back linked to Arsenal this summer would have been a better option than playing Nacho Monreal or Mathieu Flamini at center-back.
Perhaps we should be talking about Arsenal's dire need for a central defender as a short-term problem because Wenger will be able to address it again on January 1. Any reasonable person would expect the manager to right this unbelievable mistake as soon as he is allowed to do so.
We'll have to see if sanity prevails in four months, but there is little evidence that Wenger's recent transfer policy is rational.