​Once upon a time, Atlético Madrid were one of the most feared teams in Europe - nowadays, they're losing to third tier Spanish sides.

Diego Simeone's side ​lost 2-1 at Cultural Leonesa - sorry, who? - in the Copa del Rey on Thursday night and it shows just how far the mighty have fallen.

It's not surprising that these struggles are occurring, with the loss to Leonesa being the tip of the iceberg during what has been a bad season for Los Rojiblancos. They sit third in La Liga but are eight points behind Real Madrid and leaders Barcelona.

Diego Simeone

Simeone gave his thoughts on the issue in his post match interview, via Marca, saying: "I have the desire to work like every day since I arrived, the penalties or the extra time in the Champions League didn't change me, nor will going out in this round.

"You are in the position to have an opinion on what you feel and we don't have the choice but to work, me and my players."

But where have these problems come from? 

It's not an issue of desire or how much this ​Atlético team work - it is more an issue of recruitment and the lack of quality in the squad.

Looking back at the teams that won the league for Simeone and got to Champions League finals, they're incomparable to now. Diego Godín commanded from the back, Tiago and Gabi were a formidable midfield partnership, while Diego Costa and David Villa led the line superbly - not to mention Antoine Griezmann, who became one of the best players in the world under the Argentine.

Today's Atlético are simply a shadow of sides previous. Simeone hasn't been able to replace the players he has lost over the last few years or so and it is beginning to show.

Joao Felix

The obvious loss is Frenchman Griezmann to Barcelona. He was consistently the shining light in the Atlético side, scoring 133 goals in 257 games under Simeone and winning numerous individual awards in the meantime.

How did Atlético try to replace him? Well, step forward João Félix. The European Golden Boy award winner left Benfica for Madrid in the summer in a club record fee of €126m. Comparisons were made to compatriot Cristiano Ronaldo, but the 20-year-old has simply not lived up to expectations.

He has bagged just four goals in all competitions for Simeone's side - including only two in ​La Liga. In comparison, Griezmann has scored seven in the league for Barça this season. Hardly light years ahead, sure, but it's more than two.

Whether it's a lack of confidence or the fact that Félix isn't used to Simeone's defensive system, the Portuguese youngster has been a flop so far. But he isn't the only attacking option who has disappointed after moving to Wanda Metropolitano.

​Thomas Lemar is another big name signing who has largely disappointed. The Frenchman was one of the hottest young prospects in the world during his time at Monaco, but has struggled since switching the French south coast for the Spanish capital. With just four goals in 64 appearances, it's no surprise that he's been linked with a move away.

Diego Costa has not been the Diego Costa he once was since his return, while Vitolo has also been unable to add any semblance of creativity to Atlético's attacking third. ​Álvaro Morata is the only recent attacking acquisition who has arguably been a 'success'This has all led to them scoring only 22 goals in 20 La Liga games this season - the same as 17th placed Mallorca.

However, the recruitment problems don't stop there for Simeone and co. They let Godín leave on a free over the summer after almost 400 appearances in the famed red and white. Not only did they lose one of the best defenders of his generation - but also a leader.

They replaced the Uruguayan by bringing in Porto's Felipe and Espanyol's Mario Hermoso. It hasn't been the same. When José Maria Giménez got injured, the two new signings had to form a partnership at the back - but they failed.

Mario Hermoso,Felipe Augusto de Almeida

When they have played alongside each other, Atlético have managed just three clean sheets in ten games - including the shock loss to Cultural Leonesa. That is poor for a team that has historically prided itself on having one of the best defences in the world.

Of course, there have also been problems in the left back area where this side lacks a whole lot of depth. Renan Lodi is the only recognised left back in the senior squad but was recently struck down by injury. This has led to youth players and even Saúl deputising for the Brazilian. 

Unsurprisingly, that hasn't worked.

To round this off, they splashed out roughly €40m on ​Real Madrid's Marcos Llorente in an attempt to replace Rodri who left for Manchester City. Not only is it bad to pay your arch rivals €40m, but for the player to only start three La Liga games adds salt to the wounds.

Diego Simeone

As much as Simeone will bat away claims that his side are in regress, it is true. This loss to Cultural Leonesa was the first time Atlético lost to a third tier side since 2011 in Simeone's first season in charge. Gone are the days of Godín, Griezmann, Gabi and Villa.

Simeone took responsibility for the loss in the Copa del Rey - but it is time that he starts taking responsibility for some horrific recruitment.