"I have some unfinished business with Arsenal so it's a great feeling to be back," he said before the game. "Once you're a Gunner, you're always a Gunner."
Surely this was just him being cute. Wenger had pulled him out of the unemployment queue and now he was telling the fans what they wanted to hear.
Well, apparently not. Flamini will do well to keep his energy levels this high for a whole campaign. In this 1-0 win against Spurs he was fuelled by gratitude and adrenalin. In one 47-minute cameo, though, he managed to blow away the suspicion that re-signing him was an act of desperation by Wenger.
From Gonzalo Higuain to Luis Suarez and beyond, Arsenal's pursuit of players has veered from the chaotic to the downright comical.
The £40m-plus-one-pound for Suarez was not only bound to provoke Liverpool but also guaranteed to undermine Arsenal's tradition of classy dealing. It was cheap and flashy all at once.
It was an alarm bell in the night that said the board here at the Emirates Stadium are still nowhere near mastering the art of luring new players across the threshold.
So Arsenal stepped into this north London derby feeling envious, embarrassed and probably fearful of a hammering. With their squadron of fresh talent, Spurs could claim the transfer window bragging rights.
Before selling Gareth Bale to Real Madrid at 7pm (officially) they had hunted seven players down. So endowed are they with new possibilities that some very good Spurs players must be wondering whether they will ever get another kick for the club.
On the bench were Lewis Holtby, Kyle Naughton, Gylfi Sigurdsson and Sandro as well as Eric Lamela, the former Roma winger whose acquisition was closely tied up with the sale of Bale. Others, such as Aaron Lennon and Jermain Defoe, look like being history men.
Arsenal, on the other hand, cancelled all leave again and gathered who they could for the visit of a club who have recast the loss of Bale as a triumph of forward-thinking. But the human factor is not to be dismissed.
With Paulinho, Mousa Dembele and Etienne Capoue in the centre of midfield and no Bale to counter-attack Tottenham's play assumed a chess-like pace.
Plainly, at this higher level, against better opposition, the new boys were working each other out and searching for a rhythm that would make the £100 million seem money well spent.
That shape and syncopation is bound to come, but it will not be quick, if this game is any guide. Arsenal meanwhile knew exactly what they wanted to do.
Santi Cazorla and Tomas Rosicky darted between Tottenham's big obstacles. Olivier Giroud paraded his new aggression and confidence.
Theo Walcott probed the right to set up the only goal of the game. In the north London's red zone, everyone knows his job, because Wenger has been handing out the briefs since 1996. In the white one, they are still standing around a lot waiting to be told what to do.
For Arsenal, then, it was all rejoicing and comedy at Tottenham's expense. But it was not vindication. Ineptitude in the transfer market will not be erased by a 1-0 win, however satisfying.
Even as Arsenal celebrated, they moved into the last 24 hours of the window: a wretched pork barrel for agents and players that always causes Wenger to hold his nose.
By morning, when the elation has worn off, Arsenal's supporters will still be hungry for change, for progress. Many will still feel jealous of Spurs and their £100m spend.
Squad strengthening should not be like the slow dance at the disco. Arsenal should have made their moves long ago. With so few players capable of challenging for the league title, they are placing a terrible burden on those who do most of the work.
Similarly the 11 who started here need to see that the club will compete with Chelsea, Spurs and the two Manchester giants in the market, which has changed dramatically since Wenger was able to butterfly-hunt in France and Africa in his early years. There are more big financial players now: Sheikhs, oligarchs and American speculators.
This win was deeply satisfying for Arsenal, but it changed little. Flamini's presence was a reminder of what it used to be like around here. They still need to reconnect that past with their future.