If you've been keeping even the must cursory of watches over European football for the last few months, it probably won't have escaped your attention that Borussia Dortmund are having a bit of a bad time of it.
Yes, 2011 and 2012 Bundesliga winners Dortmund. Yes, 2013 Champions League finalists Dortmund. Yes, Marco Reus, Mats Hummels, Jürgen Klopp Dortmund. And not just a Manchester United, Liverpool style mid-table slump; before a recent victory over Freiburg, they were right at the very foot of the Bundesliga table, behind even little old Paderborn.
There are many who believe that that vital victory at Freiburg can be the belated catalyst to kickstart their season, and this is highly possible. In terms of individual talent, Die Schwarzgelben still have one of the most talented squads in Europe, as shown by their table-topping exploits in their Champions League group with Arsenal, Anderlecht and Galatasaray. Reus' recent, unexpected contract extension proves that the club's stars are not abandoning ship just yet.
It is too early to write them off, though they are still languishing in a relegation play-off spot. The competitive nature of the Bundesliga means they are only six points off the top half, but a relegation scrap is not an easy situation from which to escape. An eventual relegation would not be unprecedented - as these sorry examples prove, there is no such thing as 'too big to go down'.
Nürnberg 1968/69
Given that no side has been relegated from the Bundesliga more than Nürnberg's seven, it isn't wholly surprising that Der Club make an appearance on this list. However, they had been champions just a year before. They were dispatched from the European Cup in the first round by Ajax - no shame in that - and spent most of the season in a respectable, if disappointing, mid-table position. However, a pre-season squad overhaul including the sale of championship-winning top scorer Franz Brungs, soon came back to haunt the club and a steady descent down the table began after Christmas. With their fate in their own hands on the final day of the season, a 3-0 drubbing at FC Köln confirmed their ignominious demise. 17th-placed Dortmund, who won their final game, could hardly believe their luck.
River Plate 2010/11
River Plate of Argentina are one of the biggest clubs in South America, and as such their first ever relegation four years ago made waves around the footballing world. The club formerly graced by Alfredo Di Stéfano, Enzo Francescoli and Hernán Crespo have countless Primera División titles and two Copa Libertadores to their name, and they too went into the final day of the fateful season with their destiny in their own control, needing a two-goal win to complete a desperate escape from a humiliating relegation. Mariano Pavone put the giants 1-0 up in the opening five minutes to give a glimmer of hope, but an equaliser from opponents Belgrano broke River hearts, while a late missed Pavone penalty rubbed salt into the barely believable wounds. At least 25 were wounded in the resulting riots as local police used water cannons to quell the crowds, who admittedly didn't have to suffer for too long - River won the Second Division at the first time of asking.
Villarreal 2011/12
While River were bouncing back, Spain's Yellow Submarine were at their lowest ebb. With a trio of some of Europe's brightest talents - Santi Cazorla, Guiseppe Rossi and Nilmar - leading the line, Villarreal had qualified for the Champions League the previous season, and the sale of injury-plagued playmaker Cazorla to mid-table Málaga at the start of the season didn't seem to pose too much of a threat. Then the unthinkable happened. Cazorla went on to enter the form of his life, earning a big-money move to the Premier League with Arsenal, while Nilmar and Rossi managed just 30 league appearances and seven goals between them as an injury hoodoo followed the club at every turn. Beloved chairman Fernando Roig was reduced to tears on the final day as Falcao's thunderous last-minute header relegated his club after a season which saw three managerial changes from a traditionally patient chairman. Thankfully for Roig, they too bounced straight back from the depths of the Second Division and have gone from strength to strength since.
Leeds United 2003/04
'Doing a Leeds' is now part of the common football vocabulary, such was the impact of the former giants' relegation after years of financial bungling and a year of on-field bottling. The team was not what it had been, English champions and 2001/02 Champions League semi-finalists with stars such as Rio Ferdinand, Robbie Fowler and Jonathan Woodgate, but some key players remained. However, players like Mark Viduka and David Batty were not enough to arrest an inevitable decline which began when huge debts had to be offset by player sales, and began with an embarrassing 4-1 defeat at Bolton Wanderers. Despite a bright future predicted for young hot-shots such as Aaron Lennon and James Milner, this slide was not arrested as Villarreal's and River Plate's had been, as what was once the biggest club in England entered administration and dropped down to League One in 2007. Though the last few years have been spent in the Championship, there has been no indication that Leeds can ever return to the heady heights which had been built to under ultimately feeble foundations.
There are, in truth, too many potential candidates to go into one article, and not all are clear-cut cases of poor performance. Juventus' involvement in the 2006 Calciopoli scandal saw inarguably the greatest ever side to be relegated, with Gianluigi Buffon, Alessandro Del Piero and Pavel Nedvěd all choosing to ply their trade in Serie B for a year. Middlesbrough's cosmopolitan side of Juninho, Emerson and Fabrizio Ravanelli lost both domestic cup finals before being relegated on the final day having been docked points for failing to fulfil a fixture with Blackburn. Stefan Effenberg, Brian Laudrup and Gabriel Batistuta sampled the bitter taste of relegation with Fiorentina in 1993. If it needed to be told to Dortmund fans - and Evertonians could do worse than to listen up - relegation may be unthinkable, but it is far from impossible.