It's easy to forget just how crazy the money in football really is.

Ever since Neymar moved to Paris Saint-Germain for £198 million, the transfer market has inflated through the ceiling and even squad players are moving for astonishing amounts of money.

As a result, some of the world's biggest teams often select a seven-player bench that is worth more than the starting XIs of many mid-table and lower-league outfits.

And that idea clearly had great resonance with Marca, who decided to look at the most expensive players in the world who 'haven't managed to establish themselves into their teams' first XI.'

Ranging from €47 million to €125 million transfer fees, their 10 selections prove that being a big-money buy doesn't guarantee you game time - and the players can be checked out down below.

10. Mesut Ozil (Arsenal) - €47 million

This is more to do with the fact Unai Emery doesn't seem to trust the German as opposed to him playing badly at the moment and his performance at Liverpool suggests far more game time is due.

9. Ferland Mendy (Real Madrid) - €48 million

It's still early days for the highly-talented Frenchman at the Bernabeu and he could have to wait a few seasons before he consistently usurps Marcelo. He's started four times for Real this season.

8. Eder Militao (Real Madrid) - €50 million

Trust us when we say this will turn out to be something of a theme. With just two starts in La Liga, Militao is another Real procurement that Zinedine Zidane is being cautious not to overexpose. 

7. Naby Keita (Liverpool) - €60 million

The former RB Leipzig player certainly hasn't flopped on Merseyside, but he's one of the least consistent players in a Liverpool midfield built on sturdiness and reliability.

6. Anthony Martial (Manchester United) - €60 million

Hmm. This is the one Marca pick that we're not entirely sure about, because Ole Gunnar Solskjaer has invested a lot of trust in the Frenchman and five goals in nine games has largely justified that.

5. Luka Jovic (Real Madrid) - €60 million

The fact reports suggested Jovic could have been immediately loaned out and the relief with which he celebrated his first goal tells you everything you need to know about his tough start in Spain.

4. Joao Cancelo (Manchester City) - €65 million

Pep Guardiola admitted that the former Juventus full-back has struggled to adapt to the Premier League and three starts this season suggests the City boss isn't kidding. 

3. Riyad Mahrez (Manchester City) - €67 million

In truth, the 2018 move for Mahrez always looked unnecessary and the Algerian has never established himself as a consistent fixture amongst the abundance of riches at the Etihad Stadium.

2. James Rodriguez (Real Madrid) - €75 million

After two seasons on loan at Bayern Munich, it came as a surprise to see Rodriguez get a second chance in Spain, but Zidane has continued to ration game time for the Colombian.

1. Ousmane Dembele (Barcelona) - €125 million

Dembele has been one massive frustration. Now in his third season at Camp Nou, Ernesto Valverde must be wondering if the 22-year-old will ever reach the potential that's been long expected of him.

That's no less than €657 million-worth of talent and it's spending most of its time on the bench.

It seems Real Madrid have a big problem with integrating some of their new signings, while clubs like Manchester City and Barcelona also have some expensive problems on their mind.

No matter how much footballers move for and how much currency floats around the game, you can only ever field 11 players and even some of the biggest signings in history can't avoid that fact.