Former Arsenal defender Sol Campbell says the Gunners need more leaders on the pitch if they want to win another Premier League title.
Campbell is the latest to question the mental toughness of Arsene Wenger's side following Saturday's 3-1 loss at Chelsea, which left them 12 points behind the league leaders.
And the ex-England international, who was part of Arsenal's 2003-04 "Invincibles" side, said the current team do not have enough big characters on the pitch to adjust to setbacks.
"The guys who will say something on the pitch, you don't need one, you need almost four or five saying their stuff if things are not going right," Campbell told Sky Sports.
"I don't know what's happening now, but when I was there we used to police it ourselves. We had the characters to police it ourselves. We didn't allow the whole 45 minutes to go by, we would address it on the pitch because if you wait for 45 minutes and you are in, you might be 2-0 down.
"And we had the characters you know would say something -- Patrick [Vieira] would say something, Tony [Adams], Martin Keown, David Seaman, all these guys. From the front, Thierry [Henry], Dennis Bergkamp, all these guys would chip in on the pitch while the game was going on. That's the key, you've got to have those characters on the pitch."
Arsenal have been without captain Per Mertesacker all season because of an injury, while stand-in skipper Laurent Koscielny is not known for being outspoken on the pitch. Granit Xhaka was hailed for his leadership qualities when he was brought in last summer, but the Switzerland international was suspended for the Chelsea game.
Campbell also questioned whether Arsene Wenger's style of attacking football is holding the Gunners back.
"I think with Arsene, I think he believes he can win the league. I think he starts every season saying, 'right, we can win the league playing this style of football,'" Campbell said. "Obviously reality kicks in halfway through the season. It's not that easy because you need the personnel on the pitch."