Bayern Munich are watching a golden era disappear off into the sunset after their Villarreal debacle

The writing has been on the wall for a while but Tuesday night's Champions League defeat to Villarreal spelled it out clearly - Bayern Munich are starting to fall apart.

Samuel Chukwueze stunned the Allianz Arena into silence when he struck at the death to knock the German giants out of the Champions League.

Despite losing the first leg of their quarter-final tie 1-0 in Spain, Bayern were widely expected to overturn the defeat and progress to the final four of the competition. Instead they suffered European embarrassment at the hands of the seventh-placed LaLiga side.

It was the first time Bayern have failed to win consecutive games at any stage of the competition since exiting to Liverpool in the 2018-19 season.

The defeat also signalled the second consecutive year Bayern have been knocked out at the quarter-final stage.

Last year, they lost to Paris Saint-Germain and it subsequently became the first time in a decade they had been knocked out by a team who did not go on to reach the final.

But that no longer appears to be a blip after they no longer looked shades of the European elite they once were against Villarreal.

Bayern are on track for their tenth Bundesliga title in ten years as they sit nine points clear of Borussia Dortmund with six games left to play.

But a league title alone cannot be counted as a successful season for the Bavarians as they failed to win the DFB-Pokal and fell short of their 'minimum goal' of the Champions League semi finals.

Even boss Julian Nagelsmann admitted this season cannot be considered a success for his side, insisting the Bundesliga is 'not enough'.

Their Champions League exit in particular has posed questions over the Bavarian team's future as they risk losing their place among Europe's highest echelons.

As Bayern appear to be struggling, where are the cracks beginning to show for one of Europe's Behemoths?

Losing top stars

The first hint the strength of Bayern's squad was waning came when the club were unable to hold on to David Alaba last summer, preceded by the loss of Thiago Alcantara to Liverpool the previous year.

Now the loss of their top stars could come thick and fast.

Serge Gnabry, Manuel Neuer and Thomas Muller all have contracts expiring in June 2023.

Gnabry is already reportedly thinking about leaving Bayern Munich following interest from around Europe.

But the greatest dilemma comes in the form of Robert Lewandowski as the shadow of speculation looms over the club this season.

Uncertainty over the Pole's future in Bavaria has plagued Bayern Munich this season as the 33-year-old striker's current deal with the club expires in the summer of 2023.

Earlier this week, reports suggested that Lewandowski had informed Bayern that he won't sign a new contract with the club and has agreed terms with Barcelona.

Speaking ahead of Bayern's exit at the hands of Villarreal, club CEO Oliver Kahn insisted the club would be 'crazy' to let their prolific marksman leave.

But with the summer transfer window on the horizon, he has yet to put pen to paper on a new deal.

Meanwhile, manager Julian Nagelsmann insisted the noise off the pitch wasn't affecting Bayern's performance on it.

But the fact remains that Lewandowski has been the side's main goal supplier, scoring at least 40 goals in each of the last seven seasons.

With his stunning record Lewandowski has won the Bundesliga title every year he has been at the club, lifted the UEFA Champions League, the UEFA Super Cup, the FIFA Club World Cup, the DFB-Pokal (3) and the German Supercup (5).

The inability to hold on to the high profile striker would not only dent Bayern's goal influx but also their image as one of Europe's top clubs.

Ageing squad

With six current members over the age of 30, Bayern's squad has an average age of 25.8.

While that is actually lower than their European rivals such as the likes of Liverpool and Real Madrid, it still feels that Bayern's squad needs freshening up.

Both Manuel Neuer and Thomas Muller have been at the club for over ten years, while Lewandowski has been plying his trade in Munich for eight.

Additionally, four current players will be 30 or just turning 30 by the time their current contracts expire.

It appears Bayern are relying too heavily on their ageing stars to carry them across the line, rather than rejuvenate the squad with fresher and younger talent.

But how much longer can they successfully continue to do so?

It's not just the ageing of the squad but also its lack of depth that is creating issues for Bayern.

The club's sporting director Hasan 'Brazzo' Salihamidzic and technical director Marco Neppe recognise the team has issues with depth, according to Sport1, which buys Nagelsmann time - at least until the summer window opens.

The club have let players such as Alaba and Thiago head out the door but have failed to adequately replace them.

The lack of options to bring off the bench against Villarreal was a clear indicator that Bayern need to bring in reinforcements in summer.

Financial issues

The Covid-19 pandemic spared no prisoners in the football world as clubs from the lower leagues up to the dizzying heights of the top-flight suffered a financial blow.

Bayern in particular have emerged from the pandemic in decline as their annual profits have shrunk from a healthy €52.5million (£43.7m) before the pandemic to €1.9m (£1.58m) in 2020-21, according to The Athletic.

Given their issues with an ageing squad, it is clear that Bayern need to back Nagelsmann with transfers in the summer but how they fund it, not so much.

Bayern have built their success on the ability to break even but find themselves unable to compete with the Middle Eastern wealth of the likes of PSG.

The German side have also arguably been overpaying for players and seeing no real return on the pitch.

The error-prone Dayot Upamecano cost the club €42.5m (£38.25m), while they forked out £72m and £37.35m for injury-prone duo Lucas Hernandez and Corentin Tolisso respectively.

Millions of pounds that could have been spread out across the pitch but have instead left the squad threadbare.

When faced with the need to freshen things up in the second half against Villarreal, Nagelsmann only really had Serge Gnabry to turn to on the bench. Instead the manager shoehorned left-back Alphonso Davies into an attacking role.

The only attractive prospect to losing a star player such as Robert Lewandowski would be the financial gain but he could leave on a free transfer next summer and Bayern will not even reap the monetary rewards.

Bayern find themselves trapped in a cycle - needing to rejuvenate their squad but lacking the funds to hit the market.

Managerial pedigree

Julian Nagelsmann arrived at Bayern as a young manager with plenty of hype surrounding him after guiding RB Leipzig to third in the Bundesliga in his first season at the club and second in the following campaign.

However, arriving in the wake of Hansi Flick's extremely successful tenure was always going to present a challenge for Nagelsmann to battle his way out of the former boss's shadow.

But Nagelsmann has arguably faced a trickier season than any could have expected, with the Bundesliga the only success he has to show for it.

The young manager clearly has a vision on how he wants his side to look but patience is not a virtue found in top football these days.

He has faced criticism for his tactics, player management and formation with the latest backlash coming in the wake of Bayern's European exit.

Bayern supporters were left incensed by Nagelsmann's decision to substitute Alphonso Davies for Lucas Hernandez.

The boss made the change just one minute before Samuel Chukwueze struck to send Villarreal through, with the striker bullying substitute Davies for his goal.

Following the game fans took to social media to lash out at the manager for the substitution, with one supporter branding it a 'suicide decision'.

Even more worryingly, the coach has also reportedly faced criticism from within his star-studded dressing room, according to Sport1.

Understandably, Nagelsmann needs more time to implement his vision at the Allianz and should be given another season despite the failures of this term.

But he quickly needs to establish consistency within his side or he risks losing the backing of the club's chiefs as well as the fans and players and Bayern bosses will be left with the failed experiment of a youthful coach.

Elite status

The German side have dominated the Champions League, being considered as semi-final contenders for the past decade and making it to at least that stage in eight of the last 13 seasons.

To truly cement their place in the competition they have only failed to make it out of the group stage once since the 1994-95 season.

But as the past two years have proven, the Bavarians are beginning to lose their grip on Europe's most coveted tournament.

According to Munich newspaper Abendzeitung, Bayern have always prided themselves on being able to offer players the 'complete package' with the club offering other incentives than mega-money salaries to lure players to the club.

But without the prestigious status as a member of Europe's elite, the guarantee of Champions League progression slipping and a concerning financial position, will Bayern be able to continue competing with other top sides?

A dent in their status also not only affects their ability to bring in big names but also to hold on to their current stars.

And the loss of their top players, such as Lewandowski, to their main rivals further damages their image on the European stage, which again generates a never-ending cycle - or rather spiral.