We have based the money spent, players and the manager of the club and their overall expectations against what was the reality to determine the most underperforming football sides ever.
For example, Schalke's 2020/21 relegation, but the underperforming United sides of the past decade are, due to the sheer quality they boasted.
Rrom the signing of Luís Figo in 2000, to the departure of Zinedine Zidane in 2006, the Real Madrid era of the early 2000s was nothing short of disastrous given the quality they had.
However, the 2003/04 season was when the club had the Galácticos at the peak of their powers and it was expected they would win absolutely everything. These were the days when Premier League clubs struggled in Europe, with Manchester United the only club to reach the Champions League final since its rebranding in 1993, while Italian clubs and Bayern Munich were far from the sides they were in the 1990s. Also in Spain, it was the pre-Lionel Messi era at Barcelona, and Atletico Madrid were nowhere near the side they are today under Diego Simeone and it should have been a comfortable La Liga title for Real.
Roberto Carlos, Ronaldo, Raul, Luis Figo, Ivan Helguera, Casillas, and David Beckham made up a team that to this day, is arguably the greatest we've ever seen on paper. However, the club finished fourth with these names back in 2003/04, losing 10 times in La Liga, were knocked out in the Champions League by Monaco, and even lost the Copa del Rey final to Real Zaragoza.
Has a team ever underperformed more?
AC Milan have had many underperforming seasons in the past decade, as they failed to qualify for the Champions League for seven years in a row until doing so last season for the first time since 2012/13.
Similar feats happened during the 2000s and 1990s, but in 2000/01, the club finished sixth in Serie A with only 49 points, and if it wasn't for Andriy Shevchenko's 24 goals in the league, the club could have genuinely fought relegation, considering these goals were almost 50% of the 56 they netted in total.
In fact, they finished 12 points above the drop zone and 26 off champions Roma at a time where they were just two seasons off winning the Champions League again.
In what is easily the worst title defence on this list and perhaps the worst title defence in the history of Europe's top five leagues, AC Milan saw their Serie A crown all but gone after just a few games where they eventually finished 11th and a stunning six points away from relegation and 22 points off the top.
Milan ended up losing 13 times across the 34 league games that season, and if it wasn't for George Weah's 13 league goals, the Italian giants could well have been relegated.
The club also boasted sensational talents as well like Roberto Baggio, Franchino Baresi, Paulo Maldini, Demetrio Albertini, Jesper Blomqvist, Edgar Davids, Cristophe Dugarry, Marcel Desailly, and Zvonimir Boban.
In truth, it may well be the most underperforming season we've ever seen.
The 1990s was a complete nightmare for Liverpool as when the First Division changed to the Premier League, the club would fail to challenge for titles and see rivals Manchester United win near enough every league trophy.
However, their 1993/94 campaign remains perhaps their worst in the Premier League era as they finished eighth and were even knocked out of the FA Cup by Bristol City.
The Reds would also be knocked out of the League Cup by Wimbledon in the fourth round, and if it wasn't for Ian Rush's 19 goals and Robbie Fowler's 18 across the board, the club could easily have finished as low as 13th.
Moving on to the most modern side, and it's Manchester United's current 2021/22 side that should well have been competing for the title with what they have on offer.
The club made drastic moves under Ole Gunnar Solskjaer during 2018-2020, where the club finished third in 2019/20, and then second in last season's campaign and it looked as if they were just a few signings away from competing for the league title again.
In came the football's greatest ever goalscorer, Cristiano Ronaldo, one of the world's best wingers and long sought after wonderkid, Jadon Sancho, as well as four-time Champions League winner Raphael Varane.
With this, you would assume United would eventually challenge for the title, considering they also had elite names like Bruno Fernandes, Paul Pogba, and Edinson Cavani. No. They currently sit seventh, are already out of the League Cup, while Solskjaer was sacked in November after losing 5-0 to rivals Liverpool and 2-0 to city rivals, Manchester City, and 4-1 to the relegation-fighting Watford.
Now, they'll be lucky if they get into the Europa Conference League.
Juventus' 1998/99 side was a thing of legends and it is incredible to think the attempted defence of their title came by them finishing seventh in that season.
You only have to hear the likes of the former United players during their treble-winning season to get an understanding of just how tough this side were to play against, but in stunning fashion, despite putting up a Champions League fight to the last four, they finished 16 points off champions Milan, missed out of the Champions League altogether for the following season, and finished 15 points above relegation.
What made this so damning, however, was the club's team. Didier Deschamps, Ciro Ferrara, Edgar Davis, Filippo Inzaghi, Alessandro Birindelli, Zinedine Zidane, Antonio Conte, and a young Thierry Henry made up one of the 1990s most threatening sides. They also had Alessandro Del Piero in their ranks, but he had a season-long injury and played just eight times.
Moving onto a Premier League title defence with Chelsea's worst-ever attempt under Jose Mourinho. "The Chosen One" returned to Stamford Bridge in 2013 and finished third in his first season back, but in the following campaign, his Chelsea side romped home by winning 26 of the 38 games, losing only three times and had the title all but mathematically wrapped up by February.
The only major difference to that 2014/15 title-winning team and this one was the departure of Didier Drogba for the second time, but he literally came back just to be a backup to Diego Costa anyway. It was, however, the first season without Petr Cech, but the club was happy to bring in Thibaut Courtois as the number one after years of excelling at Atletico.
The team was near enough the exact same with Mourinho still there too. However, in extraordinary fashion, the club finished 10th, lost just as many games as they won (12), conceded 53 times, and were 13 points above the relegation zone and an almighty 31 adrift of champions, Leicester City.
More embarrassingly for the class of 2015/16 was the fact the club reclaimed the title with a record-breaking season the following campaign that saw them earn 93 points the season after, proving just how bad they actually were.
We're back again with United, but this one must be taken with a pinch of salt for one reason only: it was the first campaign without Sir Alex Ferguson in 26 years.
Nevertheless, the players remained the same as what it was the season prior where they won the title with ease, thanks to Robin van Persie's 26 league goals. On one hand, the club had a disastrous transfer window where they signed absolutely nobody worth mentioning apart from Marouane Fellaini, who although at the time was a great signing at the time, he proved to be the most anti-United player probably ever.
David Moyes took the helm after Fergie and despite many still thinking a title charge could happen, they finished seventh, as low as they ever have in the Premier League and were 22 points off the champions City. And, although an expected title charge now seems crazy in retrospect, finishing seventh was insanity and a top four battle should have been the bare minimum.
It's rare that a Bundesliga season will finish with Bayern Munich not as the champions, but in 1991/92 they entered the season after finishing second the season prior and the champions the season before that, and this remains their worst campaign in the past 30 years.
Bayern finished 10th in the Bundesliga having sixteen fewer points than champions VfB Stuttgart, and it was their worst finish since ending the campaign in 12th back in 1977/78. Worse yet, in one of the all-time DFB-Pokal upsets, the Bundesliga giants lost to FC Homburg 4-2, and their UEFA Cup campaign also lasted just two rounds when they were eliminated by Danish side, Boldklubben 1903.
It remains probably their worst ever season across the board since earning their way into the Bundesliga in 1963, and perhaps the worst season on this list considering their defeats to lower-ranked sides in cup competitions as well as their league finish.
It's hard to know what to expect from Sporting given this is only their second game without Ruben Amorim, and their first game came against lower league opposition. Regardless, it ...
