Arsenal fans may not see the best of club record signing Alexandre Lacazette for months, says former Gunners midfielder Robert Pires.
Pires said it took him more than six months to settle after his 2000 move.
His fellow Frenchman Lacazette, a 26-year-old striker, cost the Gunners £46.5m from Lyon after scoring 28 goals in Ligue 1 last season.
"I think he'll be a success. But maybe he will need time to adapt," Pires, who was at Arsenal for six years, said.
Lacazette scored on his first Arsenal appearance in a pre-season game against Sydney FC last week, and is likely to face Chelsea in Beijing on Saturday.
But former France international Pires - who also made the direct move from Ligue 1 to the Premier League - believes it will take time for Lacazette to get used to English football.
"He is a good striker who has scored a lot of goals with Lyon. Of course it will be very difficult in the beginning because when you play in France and move to England it is not the same, it is very aggressive.
"Maybe he will need time for the adaptation but everyone around him is very important, especially the French connection.
"But to make the adaption, to find the rhythm and the tempo, for me it took six or seven months. It was very tough, for me it was the aggression and intensity."
Pires said he initially thought he had made a mistake signing for Arsenal from Marseille because of the physical nature of the game in England.
He said: "It was my first game away at Sunderland and Arsene Wenger said 'Robert, I know you are a bit upset because you want to play but I prefer if you are on the bench and you can watch the game, the fight and the tempo'.
"After 20 minutes sat on the bench I said to myself 'what are you doing here?' because it was very, very difficult. I remember one tackle from Patrick Vieira and I thought this football wasn't for me.
"It was very difficult and it is about adaptation. If you play in France, Spain or Italy it is not the same football."
Pires also said that 21-year-old Monaco winger Thomas Lemar, who has been linked with a move to Arsenal, "is one of the best French players".
"I love Lemar. He played very well last season with Monaco in the Champions League. He is a young player with good technique, a good left foot, he can do a good cross and score good goals. For me, he has a very good profile to play for Arsenal."