No prizes for guessing this week's topic, and I apologise in advance for a potential fortnight writing about the big two, but c'est la vie. One interesting aspect of 'El Clásico' anyway is the fact that there is always a before and an after, a pre-date and a post-date. It's very rare for a Barça v Real Madrid to be played outside of the context of the top three, and next week's clash is no exception.
If it's anywhere near as good as last season's 3-3 draw in the Camp Nou then we're in for a treat, but let's not raise the expectations too high for now. It may be a more cautious affair, since a point would suit Madrid just fine, keeping them four points ahead and more or less assuring them of the leading spot at the half-way stage to the season.
However, as you may have read here before, the Christmas break represents a more crucial psychological frontier than the mere official completion of the 19 games in January, and Madrid have already assured themselves of a lead going into the Yuletide rest. They'd obviously prefer a seven-pointer, but that seems unlikely, despite the leader's good form.
Still, hope springs eternal. It's never a nice thing to admit, but a large percentage of Madrid must have breathed a collective sigh of relief on Saturday night at precisely 22.43 local time when Messi fell to the floor in the Mestalla and started pointing at his knee.
Through all the torment of the past months, Messi has remained constant, a delight to watch as well as an inspiration to his team-mates, in terms of simple work-rate. Madrid, like every other team on the planet, are terrified of the little Argentine, and will be relieved that they won't have to worry about him next Sunday.
But every silver lining has a cloud. Barcelona looked a different side with Eto'o up front again, apparently back to full fitness after his injury. His first goal after 12 minutes in the Valencia's Mestalla stadium was sublime, taking the ball past Marchena and Helguera, pivoting at speed onto his left foot and rifling the ball high to Cañizares' right, up where the spiders make their webs.
It was a perfect example of grace and aggression, allied to self-belief. Eto'o lacks many things, but self-confidence is not one of them. When it all comes together, there are fewer better forwards on the planet. Valencia are struggling at the moment, but it cannot be allowed to detract from the forward's performance.
Real Madrid may fear Messi, but Eto'o has habitually given them grief, right from the day he packed his Bernabéu bags and left for Mallorca. His scoring record against them is impressive, as if he needs to constantly vindicate himself in their presence. The fact that they wouldn't take him on has permanently riled him. He's always dangerous, but against Real Madrid more so.
Another question that is occupying the nation's keyboards at the moment is whether he will or whether he won't - Ronaldinho of course.
Against Valencia his expensive bum was once again warming the bench, but in a game that was pretty much resolved with half an hour to go, he didn't even get to warm up on the touchline. Short of match practice these days, a little run-out against a clueless Valencia would have done no harm, but it didn't happen. Giovani, Bojan and Deco were all brought into the fray, but not the goofy one.
One is left to one's own conclusions regarding Rijkaard's thinking, but at the moment the side don't seem to need him, with or without Messi. It may be that Rijkaard will decide to throw him in against Madrid, simply to give the opposition something to think about, but the truth is that when things are going for them, Barça seem to have quality to spare.
Gudjohnsen, for example, is a player underestimated by the Spanish press in general, but he rarely plays a poor game. On Saturday night his link play was perfect, dropping deep and helping to channel the moves, and then getting forward and threatening to score whenever the play had not come through him. He deserved his goal and looked very effective.
Now Barça will be in a better mood to take on Madrid - which is exactly how they planned it. Believe it or not, this was their first away win since they beat Levante 1-4 back in the mellow shadows of late September. Just as well that that their home record's been good.
Turning to Valencia for a moment, it was as if everything that Barça appeared to have, the home side lacked. It's easy to say that Valencia have no Messi, no Iniesta and no Xavi, but less obvious to say that they have no Gudjohnsen.
Arizmendi began the game playing behind Morientes, because of David Villa's absence, but his utter inability to link the play between the midfield and the forward line was horribly conspicuous.
Then again, it's difficult to say exactly what constitutes Valencia's midfield at the moment. Joaquín and Silva both prefer to play out wide, but if there is no-one to supply them (as there wasn't on Saturday) they both move infield where they are less effective. When Morientes went off injured, Vicente came on, but played in a withdrawn position on the left, where he simply got in the way of the theoretical link between the awful Moretti and the strangely subdued Silva.
Valencia, when they do their stuff, are all about power and speed, plus a solid rearguard. But Albelda and Marchena look suddenly less comfortable now that Ayala has gone, and Helguera simply looks lost in some sort of fog of his own making.
Once upon a time in Madrid, Helguera played as a sweeper behind Hierro and did it very effectively, until, that is, he was asked to come out of that role and play as a centre-back himself. The truth is that he doesn't do it very well. Barcelona looked (as did Chelsea last week) as if they could score every time they attacked anywhere near him, and in the end Albelda and Marchena resorted to the hard stuff in order to stem the tide.
It wasn't a pretty sight, especially given that these two are still the fulcrum of Luis Aragonés' national side. Another chap who no longer plays for the 'selección', Cañizares, was just about the only Valencia player to emerge with any credit.
Ronald Koeman and his assistant, his old buddy José Mari Bakero, are not having an easy baptism, to say the least. It must have been strange for the two of them, sitting there watching their team playing so poorly. You got the feeling that if the two of them had got changed at half-time and donned the white shirts, the Valencia midfield would have started to function.
The two of them usually dominated a certain zone of the park, where opponents would fear to tread. But they were not simply destructive. Both of them could score goals, but above all they were supreme organisers, at the same time as they protected other, more skilful team-mates. At the moment, Valencia have no organisers at all. Albelda can do the job, but not all alone. With fellow-city dwellers Levante propping up the table, it's looking like a bleak Christmas over Valencia way.
Not so in Spain's capital. As we saw last week. Atlético have finally got their act together, but Real Madrid continue their own particular rollercoaster. Have they peaked too soon? Well, that depends on whether you think they're playing really well, or if they're just continuing to be effective, in a pragmatic, Capello sort of way.
They certainly look stronger at the back now, and Pepe may yet prove to be a significant signing. He played well in midweek when Madrid won their Champions group (for the first time in three years) and looks powerful as well as good on the ball. Cannavaro is obviously a good defender, but he's not exactly Mr Big. But with Pepe alongside him, Diarra in front of him and Sergio Ramos thundering around, Madrid suddenly ooze physical power.
The recent inclusion of the Beast, Baptista, is also significant in this sense, and shows how Schuster manages to see the worth in everyone. Baptista is indeed a decent player, but also a physically powerful one; so by playing him 'in the hole', Raúl and Van Nistlerooy seem to get even more goodies coming their way.
The midfield isn't quite right yet; Guti still can't hold a place down and Sneijder blows hot and cold, neat player though he is. Robinho is fine when the opposition leave space for him to operate, but I'm still not convinced by his ability to function when the going gets tough.
But something's working. Schuster has managed what no other Madrid manager has managed over the past four years; to bring the squad together in some sort of harmony, all for one and one for all. There's some steel in the collective at the moment, as evidenced by the fact that they've now won their last fifteen games on the trot in the Bernabéu.
Eto'o may scare them, but Van Nistlerooy also scares Barça, and for good reason. It might not turn out to be a classic clásico, but I'm sure looking forward to it.