This was the movie "Groundhog Day" revisited, but what about the next most predictable thing in football? Don't forget the part where the Arsenal hierarchy look back on another season of underachievement with Arsene Wenger as manager and then sign off on another year in charge for the Frenchman.

Only Wenger knows how that one will play out, because all of the noises emanating from the Emirates in recent months revolve around the 67-year-old deciding when he will call it a day as manager. But it is matches like these, when defeat is accompanied by humiliation -- Bayern Munich defeated Arsenal 5-1 in the last-16 first leg -- that the farcical reality of Wenger's situation becomes exposed for what it is.

Arsenal were naive and soulless, and after Gunners defender Laurent Koscielny limped off early in the second half, they were rudderless and shambolic. It was, predictably, the same old Arsenal.

At any other major club, certainly those that regard themselves as belonging to the European elite, failure is not an option. Managers and coaches may be allowed to fail once if they are lucky, but not time after time, and Wenger is a repeat offender in the Champions League. Arsenal chief executive Ivan Gazidis and club owner Stan Kroenke may cherish the stability that Wenger brings, but that stability now brings nothing but malaise.

Owner Roman Abramovich has changed managers countless times at Chelsea; it may be a chaotic approach in Arsenal's eyes, but the formula has brought success to Stamford Bridge. Manchester City have also dispensed with managers when something hasn't been working at the Etihad, and again, the trophies have continued to fill the trophy cabinet.

Manchester United enjoyed stability and success under Sir Alex Ferguson, but once the Glazer family realised neither David Moyes nor Louis van Gaal would bring the good times back, they acted quickly and ruthlessly. Time will tell if United were right to do so, and their struggles in the post-Ferguson era will undoubtedly send a chill down the spines of Gazidis and Kroenke, but the patient approach is clearly not working and the time has come to tell Wenger that his time is up.

There should be no more indulgence of a man who last won the Premier League in 2004, no more passing the buck in the boardroom and leaving it to the manager. Chelsea, City and United do not leave it to the manager; neither do Barcelona, Real Madrid or Bayern, and if Arsenal truly want to be regarded as an elite club, they must show the ruthless streak that neither Wenger nor his players have displayed in recent years.

It has become too comfortable at the Emirates, too easy for second-best to be accepted, and too common for the "prize" of Champions League qualification to be regarded as positively as an actual trophy. The only way to change that is to find a new man to shake the club out of its comfort zone.

Even Wenger's loyalists are now beginning to accept that his time is up, with this round-of-16 mauling proving the final straw.

"I feel for Arsene Wenger," former Arsenal defender Martin Keown told BT Sport. "It's almost embarrassing. They were outclassed, outplayed.

"Wenger has to be seriously considering his future now because it's embarrassing. I can't ever say I'd like to see him go, but this is his lowest point ever as Arsenal manager. He looked particularly wounded. I feel for him. He almost needs to be protected from himself. This is 20 years of work here, but this is a massive low point for him. This brings forward the change that looks likely at the end of the season. "I think it will be him that makes the decision. The realisation that the decision needs to be made is more apparent tonight."

Wenger himself proved less forthcoming about his own future. The Arsenal manager took just three questions in the postmatch press conference, speaking only of the failings on the pitch.

"It is difficult to explain," Wenger said. "I felt we had two good chances to score just before half-time, and we were unlucky for the second goal because the referee gave a corner for us at first. Then we concede the second goal, and then the most important was that we lost Koscielny. We collapsed.

"We looked mentally very jaded and very vulnerable. The last 25 minutes was a nightmare for us. We looked like we had no response. But we have to cope with the result because, no matter what we say, it will be detrimental to us after a very bad result."

Wenger's problem, however, is that his postmatch remarks could have been from any of the round-of-16 defeats his team has experienced since 2011. It's a case of simply dusting off the excuses and using them again, but supporters are growing exasperated by the lack of progress, and judging by the downcast demeanour of Alexis Sanchez as he trudged off the pitch, so are some of the players.

It will be a wrench for Arsenal when Wenger goes, but the break has to come at some point and it must happen sooner rather than later. They cannot hide behind the suggestion that the field of potential successors is bare or that a man of his lengthy service deserves more respect and the privilege of choosing his own departure date.

Arsenal's failure to make strides on the pitch should now deny Wenger the right to decide when he goes. It's time for the owner and the board to raise their heads above the parapet and make the tough call, for Wenger's sake and for Arsenal's.