Arsenal's 5-1 thrashing by Bayern Munich reflected the extent of their current injury problems, but it also emphasised the underlying vulnerability that continues to undermine Arsene Wenger's team.

Defenders Hector Bellerin and Laurent Koscielny were the latest players to succumb to injury, meaning that Arsenal were missing 10 senior players for Wednesday's game at the Allianz Arena.

But for a side nurturing Premier League title aspirations, it was a humiliating loss -- Arsenal's joint-heaviest in the Champions League -- and left their hopes of reaching the last 16 dangling by a thread.

"They came on the pitch just like, 'Beat us,'" said unimpressed former Arsenal midfielder Emmanuel Petit. "No character, no passion on the pitch."

The British press did not mince their words on Thursday either, with 'Mullered' -- a play on the name of two-goal Bayern forward Thomas Muller -- the headline of choice on several back pages.

While acknowledging Bayern's clear superiority, the verdicts were all the more damning because Arsenal's recent form has sparked hope that this may be the season that they end their 11-year wait for a league title.

A run of five straight wins, including a ruthless 3-0 defeat of Manchester United, has left Arsenal level on 25 points with leaders Manchester City after 11 games.

With Chelsea flatlining and United enduring a chronic goal shortage, Arsenal are widely seen as City's most credible rivals, but it is often a case of one step forward, two steps back.

Arsenal can outclass United and beat Bayern 2-0, in the reverse fixture, but also lose to Olympiakos and Dinamo Zagreb and crash out of the League Cup after a 3-0 defeat at second-tier Sheffield Wednesday.

It is a paradox that means that, in spite of their nascent title ambitions, they have now lost six times at this stage of the season, across all competitions, for the first time since 1991.

Arsenal badly missed Bellerin and Koscielny in Munich, with Koscielny's deputy Gabriel at fault for the opening goal and stand-in right-back Mathieu Debuchy repeatedly embarrassed by Kingsley Coman and Douglas Costa.

Wenger admitted that Arsenal had been "extremely poor defensively".

He added: "The funny thing was that when we went forward every time we looked like we could create chances, but with a defensive performance like that you are going nowhere."

Any team would be weakened by such an injury glut, but it remains a peculiar quirk of Arsenal's that they seem unable to conceal their own weaknesses, be it exposing themselves to counter-attacks by flooding forward in cavalier fashion or, as against Bayern, not doing enough to protect their vulnerability at the back.

"Arsenal's full-backs had little or no protection and that is where all the chances came from," said former Liverpool defender Mark Lawrenson, analysing the match for BBC radio.

"You cannot give a team so much width and not expect them to create so many chances. Against the top teams, you cannot have one weakness. They will keep exposing it."

With Alex Oxlade-Chamberlain, Aaron Ramsey and Theo Walcott also currently sidelined, Arsenal's right flank has been decimated ahead of Sunday's north London derby against in-form Tottenham Hotspur.

Beyond that, their final two Group F games, both of which they must win to stand any chance of reaching the knockout phase, loom on the horizon.

They host Zagreb on November 24 and then play away to Olympiakos in Piraeus -- where Arsenal have lost on their three previous visits -- on December 9.

As last month's victory over Bayern proved, they are all matches that Arsenal are capable of winning, but equally, there are no guarantees about which incarnation of Wenger's team will show up.

"You might get the Arsenal you got against Bayern Munich at the Emirates," said former Arsenal striker Ian Wright on BT Sport.

"It's up to Arsenal to beat Olympiakos in Olympiakos (Piraeus), which they've not done. It's not easy, but you don't know what Arsenal you're going to get."