Emmanuel Petit has labelled Arsenal's 4-0 defeat to AC Milan on Wednesday a "disgrace" and called for Arsene Wenger to abandon his reliance on youth players if he hopes to end the club's trophy drought.
The Gunner's Champions League quarter-final prospects were dealt a severe blow at the San Siro when they were comprehensively beaten by Milan in the first leg of the last 16.
Arsenal were second best from the minute Kevin-Prince Boateng gave Milan the lead midway through the first half.
A brace from Brazil international Robinho and a Zlatan Ibrahimovic penalty sealed victory for Milan and condemned Arsenal to their heaviest European defeat.
And former Arsenal midfielder Petit believes Wenger should waste no time in rebuilding for next season if they are to become competitors, rather than mere participants, in the Premier League.
"The match was a disgrace. I agree with Wenger that it is surely the worst performance by the club in Europe for a long time. I thought about what had become of the team that I knew," Petit told So Foot.
"It's worse than I thought; they did not replace the departures of Fabregas and Nasri. It is an abyss that gets worse every weekend.
"And what is perhaps the most worrying thing is to say that the club will not do anything this summer to stop the decline. They will not compete with the current high prices in the transfer market and I think they are right. But for two seasons, the level of the team is down. I wonder about the future of the club. Arsene must quickly regain balance."
Petit believes that Arsenal's problems stem from a rush to replace Cesc Fabregas and Samir Nasri at the end of last summer's transfer window and suggested that, without their former captain, the club are a shadow of their former selves.
"The problem is that [last season] the club compensated for its lack of physical intensity with [Cesc] Fabregas. With him, Arsenal were the best team to watch in Europe behind Barcelona," he said.
"[But now] in midfield there is nothing, the defense is constantly under construction. Fortunately they have [Robin] van Persie, but he could leave next summer.
"I'm not saying Arsenal must recruit at any cost. But they shouldn't look sloppy and rushed like in the transfer window last August."
Petit singled out Theo Walcott and Aaron Ramsey for particular criticism, saying the former had failed to fulfil his potential while the latter looked out of place at the San Siro last night.
"I am sad but somehow it does not surprise me. Some young players are doing nothing to justify Arsene giving them confidence," Petit added.
"Walcott, at some point he is going to have to step up because it's been years since his style evolved. Ramsey, against Milan, it looked like it was his brother [playing].
"In behaviour, in body language, you can see they are gone. Regardless of age, Arsenal must identify some serious players to buy."
When questioned over the possibility of signing Lille striker Eden Hazard, Petit agreed that the young Belgian would be a good acquisition but cautioned that Wenger should look to bring in players with more experience if he hoped to overhaul Manchester United and Manchester City in the Premier League next season.
"Hazard was good in the Champions League [but] he should focus on his last months with Lille. According to him it looks like it's over.
"[Arsenal] need 5-6 players with a real status, big experience. 27-30 year olds, minimum. Players with a technical background, obviously but also a strong character. A bunch of guys who refuse to be defeated. Players who will give confidence to the rest of the team.
However, Petit insists Wenger still has the bare-bones of a good squad, as long as he can convince van Persie to sign a new deal at the Emirates.
"There is van Persie, [Alex] Song, [Jack] Wilshire, [Alex-Oxlade] Chamberlain... I like Vermaelen too. But the problem is that they need to have more motivation, otherwise history will repeat itself, invariably. The old Arsenal team were contenders, now they are mere participants."