After the departures of stars Robin van Persie and Alex Song, Wenger was expected to attempt to restructure his side.
But, after three early-summer signings, the Frenchman didn't make any new additions. And although the team has looked really good so far, there are gaps still to fill.
Arsenal were linked to many players over the summer, and many rumours fell through.
Here are five deals that the Gunners should have wrapped up.
Obviously, not all five of these players should have came to Arsenal, for money, or also because buying all five could leave Arsene with a slight surplus. These are just players that Arsenal should have purchased. However, two or three out of the five is probably most realistic.
Those who have stayed at the same club over the summer could also move to London in the January window.