Emmanuel Petit says the 2016-17 campaign “could be the most important season for Arsene Wenger and Arsenal”.
The Gunners have enjoyed considerable success under the guidance of their French coach, with 20 years having now passed since he first inherited the reins.
In that time he has overseen three Premier League title wins and six FA Cup successes.
Silverware has become harder to come by of late, though, with back-to-back cup triumphs in 2014 and 2015 helping to end a nine-year barren run.
Those Wembley wins have bought Wenger time, but an expectant fan base are crying out for title challenges at home and abroad.
Petit – a Premier League winner in 1997-98 – acknowledges that supporters have every right to feel frustrated and concedes that Wenger needs to put Arsenal back in contention for the very top honours if he is to see his reign stretch past next summer.
“I understand the frustration from Arsenal fans as well - I’m part of it,” the former France international told BT Sport.
“But I know as well what Arsene did for Arsenal over 20 years. His achievement for the club is huge, it’s massive.
“I always say since the being of the Premier League there’s two managers that have completely changed football in England. It’s Sir Alex Ferguson and Arsene Wenger, so I’m pretty sure the Arsenal fans understand that and keep it in their mind.
“But I understand as well their frustrations.
“For me, this season could be the most important season for Arsene and Arsenal. They have to do something in the Champions League or the Premier League.”
Arsenal are back in Champions League action on Tuesday evening, with a trip to Basel presenting them with an opportunity to end the group stage on a high.
They are already assured of a place in the last 16, but need results to work in their favour if they are to progress as group winners.
At home, meanwhile, an unbeaten run that stretches back to the opening day of the season has the Gunners handily perched just three points adrift of Premier League leaders Chelsea.