Former midfielder Paul Merson said Arsene Wenger was so far ahead of his time when he arrived at Arsenal "it was scary" as the long-serving Frenchman prepares to leave the club.
Arsenal manager Wenger has announced he will leave the London club at the end of the season, having won three Premier League titles and seven FA Cups during his 22 years in charge.
And Merson paid tribute to the 68-year-old, who stunned him with his tactics and ideas when he arrived from Japan in 1996, while calling on Arsenal fans to give Wenger a fitting send-off.
"He is a legend," Merson told Sky Sports News. "The word 'legend' is used loosely in football but, at Arsenal, there's no doubt about it, he's a legend.
"If fans don't turn up now for the West Ham game and pack that place out, they need real questions asked about them and whether they are Arsenal fans or glory hunters."
He continued: "The players [in 1996] were like, 'What? Who's he?' He came in, talked like Inspector Clouseau [from The Pink Panther] and didn't look like a football man. He changed so much. He was so far ahead of his time, it was scary.
"When [Wenger] came in, after a week, the players were there at nine o'clock in the morning, waiting for training. His training methods, his ideas..."
Merson believes the turning point for Wenger and Arsenal was the departure of vice-chairman David Dein in 2007, in their first season at the Emirates Stadium.
"The worst thing that ever happened to that football club - bar Arsene Wenger leaving now, because we'll see where Arsenal are - was David Dein was a massive loss," Merson said.
"Arsenal played in a stadium of 38,000 people at £50 a go. They had [Thierry] Henry, [Dennis] Bergkamp, [Robert] Pires, [Emmanuel] Petit, [Patrick] Vieira, [Marc] Overmars], Lauren, [Jens] Lehmann, Sol Campbell. They were world class players.
"David Dein leaves, they go to a stadium that holds 60,000 and it costs double to get in, you do the maths - how many of them who play now are world class? [Mesut] Ozil? [Pierre-Emerick] Aubameyang, maybe? I can't reel off players.
"It's because David Dein's gone. Arsene Wenger would go 'bang', David Dein would go and get them and sort the deal out. I think he was a massive loss. I think [Wenger] missed him.
"I think the first five, six, seven years of them going to the Emirates, that wouldn't be far off his biggest feat at Arsenal. Money was tight and they still kept getting into the Champions League."