The Frenchman has played a vital role for manager Arsene Wenger since his return to the club on a free transfer this summer.
Parlour believes that Flamini deserves credit for the role he has played this season, claiming that he has added something different to the club's midfield setup.
"Flamini has been a massive signing," Parlour told talkSPORT. "The midfield has always been very good, but they were all very similar players.
"The likes of [Santi] Cazorla, [Mikel] Arteta are really good on the ball, but they had no-one in there bossing everyone around. Now suddenly Flamini has gone in there and he is starting to pull people around.
"Before he left for AC Milan he was fantastic. Now he is doing a very similar role and giving it to [Mesut] Ozil, Cazorla. He has been a real unsung hero so far."
Flamini was forced off in the first half of Arsenal's 4-1 win over Norwich City on Saturday after suffering a concussion.