Christmas is here, which means we’re halfway through the 2019/20 season.Plenty has happened already over the past few months. Some clubs and players have impressed, while others have flattered to deceive.Earlier this month, we brought you the players whose market value has increased most since the start of the season - and now it’s time to look at the footballers whose market value has decreased most during the same period of time.For various reasons, the following 25 footballers have all seen their estimated values on the transfer market dip since July.All of the figures come courtesy of the excellent Transfermarkt.

25. Isco | Real Madrid

Previous value: £54 million
Current value: £45 million

After several frustrating seasons at the Bernabeu, surely 2020 is the year that Isco leaves Real Madrid for a new challenge?

The Spanish playmaker is a wonderful footballer; a genius on his day.

But it’s been a while now since we saw Isco at his brilliant best.

Zero goals and zero assists in 13 appearances this season is evidence that he probably needs to move on soon - possibly as early as January.

24. Koke | Atletico Madrid

Previous value: £63 million
Current value: £54 million

Koke, who has spent his entire professional career with Atletico Madrid, hasn’t been great this season.

He was even whistled by his own fans at one point a couple of months back, which would have seemed inconceivable a couple of years back.

The 27-year-old should be approaching the best years of his career but he’s not really kicking on in the way most people expected he would.

23. Thiago Alcantara | Bayern Munich

Previous value: £63 million
Current value: £54 million

Thiago Alcantara is getting on a little bit now. He turns 29 in April, which may explain why his market value has decreased by £9 million in recent months.

The Spanish midfielder still features regularly for Bayern Munich, while WhoScored.com rate him as the German club’s eighth-best performing player this season, so there’s no cause for concern just yet.

22. Christian Eriksen | Tottenham

Previous value: £90 million
Current value: £81 million

Does Christian Eriksen want to be at Tottenham? Probably not. Is he still a top player? Undoubtedly.

Because the Danish player isn’t happy at Spurs, his performance levels have dipped - and his market value has decreased as a result.

Two goals and three assists in 20 appearances this season is a disappointing return from a player with so much ability. Unless Jose Mourinho can convince him to stay put, he’ll almost certainly be playing for a new club in 2020.

21. Antoine Griezmann | Barcelona

Previous value: £117 million
Current value: £108 million

For Antoine Griezmann, it was a case of now or never in the summer. The opportunity to complete a dream move to Barcelona probably wouldn’t come again - and he took it with both hands this time, 12 months after rejecting the Catalan club in order to stay with Atletico Madrid.

The Frenchman has scored eight goals and set up four more in 23 appearances since joining Barça, which is an average return.

Did Barça *really* need him? Maybe it would have been more beneficial if they’d spent the money improving other areas of their squad instead.

20. Lionel Messi | Barcelona

Previous value: £135 million
Current value: £126 million

Lionel Messi, who recently picked up a record-breaking sixth Ballon d’Or award, is still the world’s finest footballer, so take the £9 million dip in his market value with a pinch of salt. He’s still worth his weight in gold for Barcelona.

However, the legendary Argentine does turn 33 next summer, which is why his value has decreased slightly.

That said, he’s still worth an absolute fortune - and rightly so.

19. Santi Mina | Celta Vigo

Previous value: £27 million
Current value: £16.2 million

After four years at Valencia, Santi Mina returned to Celta Vigo in the summer but has struggled to score goals.

In 16 games, the 24-year-old has only found the back of the net once.

Celta are struggling at the wrong end of the La Liga table and Mina could find himself playing second-tier football next season unless he rediscovers his shooting boots during the second half of the campaign.

18. Goncalo Guedes | Valencia

Previous value: £36 million
Current value: £25.2 million

Goncalo Guedes looked absolutely brilliant for a brief period during his loan spell at Valencia in 2017 - and he ended up joining the Spanish outfit on a permanent deal from Paris Saint-Germain the following summer.

The 23-year-old, though, has failed to kick on since then and he’s no longer spoken about as one of European football’s most exciting young talents.

His market value has also suffered as a result of his underwhelming performances.

17. Rony Lopes | Sevilla

Previous value: £22.5 million
Current value: £11.25 million

Former Manchester City prospect Rony Lopes signed a five-year contract with Sevilla in the summer after leaving AS Monaco.

However, the Portuguese attacking midfielder has hardly featured for the Andalusian outfit.

The 23-year-old has played eight times in various cup competitions, including the Europa League, but has only appeared once for his current employers in the league.

A 2020 move away from the Estadio Ramon Sánchez Pizjuan wouldn’t be a shock.

16. Ivan Rakitic | Barcelona

Previous value: £36 million
Current value: £22.5 million

Ivan Rakitic has been such a good player for Barcelona since his arrival from Sevilla in 2014; however, it’s beginning to feel that his time at the Camp Nou is coming to an end.

Ernesto Valverde has only started Rakitic on a handful of occasions this season, prompting the Croatian midfielder to tell reporters earlier this month: “I don't understand the situation because I want to play. If I can play, there is no better place than Barça. I want to enjoy every day and if it can be here, much better.”

15. Marcos Alonso | Chelsea

Previous value: £36 million
Current value: £22.5 million

Marcos Alonso has been one of the Premier League’s most dangerous attacking full-backs in recent seasons, but the Spaniard has found himself in and out of Chelsea’s team since Frank Lampard was appointed manager in the summer.

His market value has subsequently dropped by £13.5 million.

14. Edinson Cavani | Paris Saint-Germain

Previous value: £36 million
Current value: £22.5 million

Edinson Cavani turns 33 in February, which means he’s approaching the autumn of his career.

However, the prolific Uruguayan striker is reportedly on the verge of sealing a move to Atletico Madrid - so Diego Simeone obviously believes he’s far from finished at the highest level.

13. Granit Xhaka | Arsenal

Previous value: £40.5 million
Current value: £27 million

To say Granit Xhaka has endured a nightmare season so far would be an understatement.

The Swiss midfielder was stripped of the captain’s armband earlier this season for telling the Arsenal fans to ‘f*** off’ after being booed at the Emirates Stadium.

A move away from Arsenal in January still appears to be likely, even though he has returned to the Gunners’ line-up in recent weeks.

12. Sergio Busquets | Barcelona

Previous value: £45 million
Current value: £31.5 million

Is Sergio Busquets’ influence on the Barcelona team beginning to wane slightly?

WhoScored.com still rate him as Barça’s fifth-best performing player this season, so perhaps not - but it just feels like the 31-year-old might be entering the early stages of decline.

He’s still a class act, mind, and easily one of the world’s very best central midfielders.

11. Cristiano Ronaldo | Juventus

Previous value: £81 million
Current value: £67.5 million

Like Messi, the decrease in Cristiano Ronaldo’s market value is purely down to the fact he’s getting older.

The Juventus star turns 35 in February but, as we saw recently with that magnificent header against Sampdoria, is still capable of producing magic on the pitch.

The truth is, if Juve were to sell him right now they’d still fetch a lot more than £67.5 million.

10. Naby Keita | Liverpool

Previous value: £54 million
Current value: £37.8 million

Naby Keita’s value has dipped £16.2 million since July, but his recent performances for Liverpool suggests there’s nothing for Jurgen Klopp to worry about.

The midfielder flattered to deceive during his debut campaign at Anfield but he’s now found his feet with the Reds and even managed to score three goals in his previous five appearances.

Expect that market value to increase in 2020.

9. Marco Asensio | Real Madrid

Previous value: £54 million
Current value: £36 million

Marco Asensio hasn’t played this season because he’s injured. The 23-year-old sadly tore his ACL during a pre-season match against Arsenal back in July.

It’s unclear whether the Spanish midfielder, who looked a future world-beater a couple of years ago, will feature between now and the end of the season.

Let’s hope he makes a full recovery and rediscovers his best form on his return to action.

8. Luka Jovic | Real Madrid

Previous value: £54 million
Current value: £36 million

Snapped up by Real Madrid in the summer after scoring 27 goals in 48 games for Eintracht Frankfurt last season, Luka Jovic has struggled during his first six months at the Bernabeu.

In 14 games, the Serbian forward has managed to score just one goal. No wonder there’s already speculation that he could be off in January.

7. Nabil Fekir | Real Betis

Previous value: £54 million
Current value: £36 million

Nabil Fekir’s reputation has taken something of a nose-dive over the past 18 months.

The French attacking midfielder was one of the most in-demand players in Europe after the 2017/18 campaign when he scored 23 goals in 40 games for Lyon.

But a disappointing 2018/19 season saw him move to Real Betis in the summer - and so far he’s scored four goals and registered two assists in La Liga.

The 26-year-old must wish he’d joined Liverpool when he had the chance.

6. Gareth Bale | Real Madrid

Previous value: £54 million
Current value: £36 million

Yep - Gareth Bale is now worth just £36 million, according to Transfermarkt. That can’t be right, can it?

The Welshman is 30 years old, but he’s still one of the world’s best attacking players on his day.

That said, he needs to leave the Bernabeu in 2020. Things have turned even more sour for the world-class forward in recent months and a move away from Real Madrid is probably in the best interests of all concerned.

5. Vinicius Junior | Real Madrid

Previous value: £63 million
Current value: £45 million

It’s important to remember that Vinicius Junior is still just 19 years old. His best years are ahead of him.

But when you’re at a club like Real Madrid, you need to impress week-in, week-out to avoid criticism.

The Brazilian winger is enduring a difficult second season at the Bernabeu, hence why his market value has dipped by £18 million in recent months, but there’s no doubt he’s a player with enormous potential.

4. Philippe Coutinho | Bayern Munich

Previous value: £81 million
Current value: £63 million

Philippe Coutinho did the right thing leaving Barcelona in the summer. His move to the Camp Nou hadn’t worked out and he desperately required a change of scenery to rediscover his form and confidence.

The Brazilian playmaker has been superb for his loan club Bayern Munich in recent weeks, but his market value has still dropped by £18 million since July.

If he continues to shine, though, expect that value to move back in the opposite direction during the first half of 2020.

3. Neymar | Paris Saint-Germain

Previous value: £162 million
Current value: £144 million

It’s no secret that Neymar was desperate to leave PSG in the summer. The world-class Brazilian was reportedly left devastated when his return to Barcelona failed to materialise.

He’s scored nine goals and registered six assists in 12 games so far this season, so it’s not as if he’s been performing badly.

But the 27-year-old’s market value has still dropped by £18 million in recent months.

2. Ousmane Dembele | Barcelona

Previous value: £90 million
Current value: £67.5 million

Is Ousmane Dembele a future world-beater - or is he actually a bit overrated?

This question will be answered over the next couple of seasons but the jury is certainly still out over the 22-year-old, who has blown hot and cold for the Catalan giants following his arrival from Borussia Dortmund in August 2017.

The French forward has bags of talent, but whether he fulfils his huge potential is another matter.

1. Eden Hazard | Real Madrid

Previous value: £135 million
Current value: £108 million

But top of the list, it’s Eden Hazard, whose value has plummeted £27 million since the beginning of the season.

With just one goal and four assists to show from his first 13 appearances for Real Madrid, it’s fair to say the Belgian has underwhelmed following his big-money move from Chelsea in the summer.

That said, it’s still early days and the former Premier League star is clearly a class act. It won’t be a surprise if he ends up hitting top gear for Los Blancos between now and the end of the current campaign.

Don’t write him off just yet.

So, there’s our top 25 - now let’s take a quick look at some of the other players whose market values have decreased this season…

Luis Suarez, Marco Reus, James Rodriguez, Emre Can, Gerard Pique and Lucas Torreira are among a handful of big-name players who have seen £9 million shaved off their respective values.

Jesse Lingard and Moise Kean, meanwhile, have both suffered a £7.2 million reduction in their values (falling from £36 million down to £28.8 million) after a string of disappointing displays.

A new year is just around the corner, however, and that presents a fresh opportunity for these players to show why their market values were so high in the first place.