Wenger and Manchester United boss Ferguson have had tremendous battles down the years and have often had verbal spats in the heat of battle. But there is huge respect between the pair and Ferguson has hit out at the criticism of Wenger.
With Arsenal having gone six years without winning a trophy and lost arguably their best player in Cesc Fabregas this summer, the knives are out for Wenger following a poor start to the new season.
And with the sale of Samir Nasri to Manchester City expected to be completed on Wednesday, when the Gunners will also face a crunch Champions League play-off second leg at Udinese with a depleted squad, there have been some questioning how much longer Wenger's 15-year tenure at the club will last.
But Ferguson believes Arsenal will not find a better manager than his old rival and has urged Wenger to reach for a set of earplugs.
"It's a crazy world we're in," Ferguson said. "It's a critical world and you only need to lose a couple of games to have critics howling down at you.
"All the talk is about Arsenal and Arsene leaving. But who can replace him? It's the most ridiculous situation. The man has been simply unbelievable. He has given Arsenal platforms they never thought they'd get to.
"He should carry on. He shouldn't listen to the critics. The one thing you need in this game is earplugs."
Despite Ferguson's sympathy for Wenger, he will be looking to pile on the misery for Arsenal, who only have one point after two Premier League games this season, when his United side host the Gunners at Old Trafford this Sunday.