The 29-year-old French midfielder signed a three-year deal with the north London club after being released by AC Milan at the end of last season.
Flamini has played an important role in front of the Arsenal defence in recent games and has started four of the Gunners’ six Premier League matches.
And Wenger has been thrilled with the way Flamini has slotted seamlessly back into his Arsenal side.
“Mathieu Flamini has given us a balance between attacking and defending,” said Wenger. “He is someone who accepts the ‘dark’ role in the team.
“Before, in big games, we looked frail defensively sometimes and he gives us more in that sense.
“I don’t know if he will turn out to be one of the most important signings I have ever made. But I think it was ‘an’ important signing.”
Wenger said that it was Flamini’s professional attitude which convinced him to re-sign the midfielder after he had trained with the Gunners over the summer.
“He is 29 now and, at that age, you know better who you are as a player,” said Wenger.
“When he first arrived here he wanted to play in a more offensive role but today he knows his qualities and accepts them.
“His attitude convinced me to sign him, because he had proposals from other clubs. But once he decided to wait on us to see if he could sign here, you thought there is something special here.”
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