Friday 22 December 2017 23:55, UK
Guillem Balague picks out six players who could make a big impact in Saturday's Clasico, live on Sky Sports.
It's a must-win game for Real Madrid, who are 11 points behind their arch-rivals, but Barcelona are undefeated in La Liga and they will be desperate to keep it that way.
Which players could make the difference? From Lionel Messi and Cristiano Ronaldo to Luka Modric and Karim Benzema, Balague gives his verdict.
Barcelona's third goal against Deportivo on Sunday started very deep, with lots of passes and movement off the ball, and Messi was at the heart of it. It was a glimpse of what he might be like in a few years, when the pace is gone but he still has the vision. Right now, though, he still has both.
Ernesto Valverde agreed to play him in the centre soon after his arrival at the club. It has affected Luis Suarez, who can't find as much space as in previous seasons, but it has allowed Messi to be even more influential, switching between playing as an attacking midfielder or as a forward.
He has got the intelligence for both roles and that is what sets him apart. He has been dropping deep and doing the job of Andres Iniesta at times, and yet he has still scored 14 goals in La Liga alone. He is the ultimate forward and we've seen that this season.
As well as scoring plenty of goals, he has hit the woodwork 12 times - seven more than any other player. It shows two things. One, that luck is not always on his side. And two, that he is still shooting more than anyone else despite sometimes doing the job of a No 10 or central midfielder.
Who in the world does that? There's nobody else. I get amazed when people still question whether he is well ahead of everybody else in the world. It's up to Madrid to stop him in Saturday's game.
With five goals in four games, Cristiano Ronaldo comes into the game in his best form of the season. He is now a striker, so the key thing for him is that he needs the service of the team. He doesn't beat defenders one-on-one anymore, instead he needs the ball in positions where he can finish in one or two touches.
He has been getting more of that service lately. He's also starting to feel comfortable in the position, and he has accepted the fact that he doesn't have to play in every single game. From that point of view, he is maturing.
Earlier in the season, he suffered from the same anxiety as the rest of the team about how Barcelona were getting away from them in La Liga. He was so desperate to make a difference that he was rushing his decisions in front of goal.
What we saw in the Club World Cup final against Gremio, however, was a player who wasn't in such a hurry. It was a better performance from him - he scored the winning goal from the free kick - and Real Madrid will need more of the same against Barcelona.
For me, Marc-Andre ter Stegen is the best goalkeeper in the world alongside David de Gea. It's not just because of his amazing saves that tend to come in every game, earning points for Barcelona, it's also the way he distributes the ball.
Ederson at Manchester City is getting to that level as well, like Jan Oblak too, but with their feet, Ter Stegen and Ederson are the best in the world right now. I met him last week and he told me he was a striker when he first started and you can tell by the way he plays his feet that the quality remains.
However, he did say that he was not at the level to play in an outfield position for Barcelona, which is obvious but nice to hear!
He is so important for Barcelona that he was rested in the 4-0 win over Deportivo because if he'd have picked up another booking he'd have missed the Clasico.
Busquets is back to his best because Barcelona are playing in a way which suits him much better. They now build from the back and attack together so it means Busquets doesn't have to go box-to-box, cover vast distances or defend large areas of the field.
It's taken a long while for the public to appreciate his worth to Barcelona and Spain - everybody thinks he is essential yet he does not feature in the top 50, which, for me, is a travesty.
Ter Stegen and Busquets are key for Barcelona at the moment. We know that Messi and Luis Suarez can score at any given moment but the difference this season is that they hardly concede.
They have the joint-best defensive record in La Liga and only conceded one goal in the Champions League knockout phase. That solidity at the back is going to be crucial against Real Madrid.
Modric is another player who is back to his best. He is better when Casemiro is present because it allows him to make those passes that break defensive lines.
He uses his pace in the first five metres to get away from opponents, he's got vision, quality and leadership. He is one of the best midfielders in the world and I cannot believe he has been at Real Madrid for six years now.
It's no coincidence that they have won so many trophies in that period - including in a calendar year for the first time in the club's history. We are talking about an historical Real Madrid and Modric is the engine and brains of the team.
Benzema is still not scoring enough. One of the reasons why he hasn't left Real Madrid is because he was signed by Florentino Perez, but also because Zidane has let the club know that if they let him go, it will be a struggle to keep him at the club.
Zidane thinks Benzema is absolutely crucial to link the midfield and the attack. It's only fair that his team-mates demand more of him in terms of goals, but he does so much more than scoring.
He has that sense, in a way like Messi, to know what the team and the game demands, whether to play the ball deeper or wider. Yes, he has lost his goalscoring touch but his instinct is still there and I think he will start scoring again.
You can see he is sharp, he has lost weight, he's in a good state and hardly gets injured these days. They are all reasons to suggest he will become important again. He has never let Real Madrid down in the big games, whether it be with a goal or an assist, and they will be hoping for another important contribution on Saturday.
