The French midfielder returned to the club in the summer after leaving the Gunners for AC Milan in 2009.
Despite being unsure whether to bring Flamini back to North London, Wenger claims that the 29-year-old's desire to play for Arsenal again convinced him that the move was right.
"I must say I was a bit reluctant to sign him at first, because I didn't like to sign the same players twice," he told the club's official website.
"But he convinced me with a frank and honest statement, wishing to play for Arsenal. He had other opportunities from clubs, but he said he missed what he had here."
Flamini has made seven appearances in all competitions for Arsenal this season.