Now, he cannot rely on the famous old competition to protect him - or his failure to win the Premier League since 2003/04 - after Watford's shock 2-1 quarter-final win at Emirates Stadium.

So no FA Cup, as good as out of the Champions League as Arsenal attempt to overturn a 2-0 deficit against holders Barcelona in the Nou Camp on Wednesday, and eight points behind Premier League leaders Leicester City after two losses and a draw in their last three league games.

The 66-year-old is a towering figure in Arsenal's history - but if The Gunners finish this season empty-handed it must be time for Wenger to consider relinquishing control of the club he has served with such distinction since September 1996.

So why should the end of Wenger's era be on the agenda?

Arsenal's lack of success?

No Arsenal fan - even Wenger's fiercest detractors - would wish to see a wonderful career peter out to the soundtrack of growing criticism after bringing four titles, which also included two doubles with the FA Cup, and six FA Cup triumphs in all.

There comes a time, however, when any manager's recent record must be subjected to close scrutiny, irrespective of the past. It is not a vendetta or a personal campaign against Wenger, simply an examination of unflattering facts.

It is the law, the reality, of football management.

And if Arsenal do not win the title this season, a campaign they have almost been waiting for in many respects, the time would be right to hand over power because there are no signs that Wenger is close to recreating his successes of the past.

If he fails again, Wenger will have faltered with Arsenal's rivals all stumbling around them. Chelsea have imploded, Manchester City have been indifferent and Manchester United have been off the radar.

It would be a desperate reflection on Wenger and his team if they fail to take advantage of that collection of circumstances.

Since that last title, on the back of 38 games unbeaten, Wenger has only finished second once, in the following season. There have been six fourth-placed finished and four seasons in third. Arsenal have rarely threatened to actually win the title again.

And if they go out to Barcelona, it is will be their sixth successive Champions League exit at the last 16 stage.

If history repeats itself this season, then it must be the end of the old "Arsene Knows" and "In Arsene We Trust" mantras, and change must be considered. Wenger cannot be immune from the normal measures of success and failure.

Toxic atmosphere at Arsenal

Any regular visitor to Emirates Stadium will sense the growing frustration and fury among Arsenal fans as their team falls short - an understandable emotion they rightly feel at this huge club.

There were reports of Arsenal supporters confronting each other after the FA Cup loss while a tetchy Wenger described criticism (justified given Arsenal's recent record) as "a farce".

Arsenal fans brandished a prominent banner at the 4-0 FA Cup fifth round replay win at Hull City bearing the words: "Arsene. Thanks For The Memories But It's Time To Say Goodbye."

The air can only be cleared by a trophy and will become more polluted by criticism should Arsenal, as they so often have under Wenger in recent times, come up short once more. Or it could be cleared by a change of manager.

There is growing unrest, not helped by Leicester City's rise to the top and north London rivals Tottenham moving into second place, with Wenger inevitably the central figure and the focal point for fans' disappointments.

This, in reality, means winning the Premier League. Surely Wenger's future now largely hinges on that.

(BBC)