By David Cartlidge (@davidjaca)
Barcelona's reaction to Juventus defeat
It has been a brutal period for Barcelona. Just three days after an impressive 3-0 win over Sevilla, they were stunned by relegation threatened Malaga. Three days later they faced Juventus in their Champions League quarter-final semi-leg clash, racking up a 3-0 defeat. The shades of Paris, which some hoped served as a wake up call, were all on display. Eight days after that, they were bounced out of the Champions League altogether.
Luis Enrique's had it rough ever since he took charge at Barça, but this is surely his most testing period yet. And it has come at the bitter end of his tenure. How Barça react will be interesting. Surely a lack of response in a Clasico would be unforgivable - and is it even unthinkable? Despite LaLiga gradually slipping from their grasp there still remains a chance for the Catalans to reclaim their crown. El Clasico is the time to prove all is not lost in this era, and something may still be salvaged.
How Real Madrid handle having an advantage
It's not often Real Madrid have found themselves in the position of having an advantage when walking into El Clasico. Rarer still to hold an advantage near the end of the season. 2011/2012 was the last time Real Madrid lifted Spain's most prestigious domestic trophy, and that has been a wait far too long for a club of their stature. There have been two Champions League successes in the period since their last LaLiga win but there's also been an underlying feeling of disappointment at Real Madrid's lack of dominance on home soil.
This is after all the team that champions themselves as Spain's team. Zinedine Zidane has been found wanting at several key moments this season and fortunately Barça have often responded in a lacklustre manner. This time around Zidane's men must be ruthless and see off their great rivals for good. Or will Zidane flatter to deceive with his team selection and substitutions once again?
Despite Barcelona's best attempts to execute a devious plan and stave off Neymar's ban, the Brazilian will not feature in El Clasico. It's a bigger problem than most facing Luis Enrique because Neymar has been outstanding of late for the team. And, quite importantly, his influence on the field takes the spotlight and pressure off Lionel Messi.
Against Juventus, it was Neymar who took it upon himself to grab the game by the scruff of the neck and unhinge the tough Italian outfit. It was to no avail, but Neymar's efforts did not go unnoticed and without him Barça are much less of a threat in attack. Paco Alcácer looks best placed to come into the side, with Luis Enrique likely opting for a 3-4-3 system.
Isco or Asensio?
It's a debate that continues to rage in Madrid; Isco or Asensio. Or more to the point, why not both? Gareth Bale's recovery from injury has only heightened further the pressure on Zinedine Zidane over his selections. The feeling is neither of the gifted Spanish midfielders feature enough for Zidane, and with both players in form it's difficult to leave either out of El Clasico.
Bale meanwhile hasn't been the same since a major injury this season, and then a recent knock pushed him out of the picture further and that is when Isco and Asensio stepped in superbly. But the Welshman remains a member of the BBC hierarchy and if deemed fit enough will feature.
Win or bust for Barcelona?
So, is it really win-or-bust for Barca?
Recent defeats at Deportivo La Coruna and Malaga have seen Barca lose ground on their great enemies, and going in to El Clasico, it's Real Madrid with a three point lead. A defeat at the Bernabeu on Sunday could therefore put Barca six points adrift, having played one more game - and with just five games left.
Any result but a win would do us no good whatsoever," said Luis Enrique in his pre-game press conference. In his final Clasico, he must win. He also might look back to the first Clasico of the season with a sense of what could've been.
Back in December, one of Sergio Ramos' many late goals earned Zidane's side a point at Camp Nou. Barca were all set for the win only to have it taken away from them at the last, and it could be that result proves vital come the end of the season.