Former Arsenal captain William Gallas says Arsene Wenger does not put the same demands on his players to win trophies as Jose Mourinho does.
Gallas, who won two Premier League titles under Mourinho at Chelsea before joining Wenger at Arsenal in 2006, is the latest former player to question whether the Gunners have the winning mentality required to become title contenders.
Arsenal fell 12 points behind Premier League leaders Chelsea with a 3-1 loss at Stamford Bridge on Saturday, and look set to miss out on the title for the 13th year in a row.
During an appearance on talkSPORT, Gallas indicated that Wenger does not put enough pressure on his players.
"[Under Mourinho] you get criticism when you don't win trophies, when you don't win games, and that is maybe the difference between Jose Mourinho and Arsene Wenger," he said.
"Mourinho wants to win every game and at the end of the season sometimes he has success but, for Arsene, Arsenal didn't win [the title] from 2004 so everybody starts to criticise him because football has changed.
"Football is about victory, about trophies. Players want to lift trophies. If you don't lift a trophy in your career, you will feel disappointed at the end of your career. I don't know what Arsenal are going to do but they have to win trophies again."
Gallas was stripped of the Arsenal captaincy in 2008 after criticising his teammates for not being "brave enough in battle" and later joined rivals Tottenham Hotspur.
Wenger's future at Arsenal is also uncertain as his contract expires this summer.
Gallas stopped short of saying Wenger should leave, but said it is clear something has to change at the club.
"Maybe they have to change something, because the fans are going to be very upset," he said. "We can't forget what [Wenger] did for the club. He did a very, very good job so sometimes you can't sack the manager like this. You have to respect the manager.
"That is why I said at the end of the season maybe the board has to speak with Arsene and try to find a solution."