The Gunners boss came under pressure from fans on Sunday when he was booed for substituting Alex Oxlade-Chamberlain for Andrey Arshavin during their 2-1 loss to Manchester United.
"I don't think his position at this club should ever be questioned," the keeper said. "He's done a magnificent job over 15 years and he's still doing it now.
"No-one will ever forget what he has done for the club. The players have been here before and we've reacted very well. I think we'll do the same thing again and make sure that this club goes in the right direction and we finish the season where we should, really.
"Hopefully, we can deal with all the pressure that's around us at the moment and live up to the expectations because these fans and this club deserve better results than it is has got in the last few weeks."
Arsenal are currently fifth in the Premier League with 36 points from 22 games.