The Ivory Coast international became the north London side’s most expensive summer signing in August as Unai Emery moved to bring him in from Lille.
Pepe has been a regular fixture in the Arsenal team so far this season but he is yet to open his account for the Gunners.
The 24-year-old has made one assist in six appearances in all competitions this term but he has so far failed to find the net with the north London side.
However, former Arsenal winger Pires is not concerned about Pepe’s start and he is backing the winger to come good eventually.
Speaking in an interview quoted by Metro, Pires said: “With Lille, he was fantastic. Last season he was one of the best players, he scored 21 or 22 goals. He’s a great player.
“Now he’s playing for Arsenal in the Premier League and he needs to adapt. It’s so difficult, very tough.
“So I want to say to the fans you need to be patient with Pepe.”
Arsenal are currently preparing for their home Premier League clash against Aston Villa at The Emirates on Sunday afternoon.
The Gunners are aiming to return to winning ways in the top flight after having lost one and drawn two of their last three games in the league.
Emery is aiming to try and steer the Gunners back towards qualification for next season’s Champions League via a top-four finish.
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