With a place in the Champions League final at stake, the last el clasico of the season could be the best of the four matches.
Fourth and final Barcelona and Real Madrid tussle needs no added spice
It will represent the flag of Catalonia behind both goals at Camp Nou, while the colours of Barca will dominate the sides of the ground, with the words "Gracies Equip!" ("Thanks, Team!" in Catalan) picked out.
Following a surprise away defeat at Real Sociedad on Saturday, Barca fans will relish this first opportunity to thank their team for their 2-0 victory in the Bernabeu last week. And they will enjoy nothing more than doing it in front of the vanquished Real Madrid players.
More on Barca v Real
The defeat at Sociedad may have seen a seven-month unbeaten league run come to an end, but it mattered little, for it followed Real's even more surprising home loss to Real Zaragoza.
With Barca eight points clear at the top of the Primera Liga and needing four points from their remaining four league games to wrap up a third consecutive championship, the title is a given.
What counts now is the Champions League. For a game sold on glamour and the prestige of boasting the best players in the world, the three most recent clasicos so far have been marred by dissent, ill-discipline and controversy.
Old battle lines have been redrawn and positions have become entrenched and bigoted.
The Spanish media bristled with indignation, but the games have been great for business and they love the drama and conjecture, the posturing and verbal jousting of the two managers, Joseph Guardiola and Jose Mourinho. And the physical jousting of several of their players.
Real and Mourinho have received the brunt of the criticism, but Barca have not covered themselves in glory either, with observers witnessing a cynical side to their pleasing, attacking game which usually delights football's purists.
Players have rightly been accused of playacting and the sight of members from both sides surrounding the referee became depressingly predictable.
To think that many of the angry foes are actually Spanish international teammates who usually call themselves friends when they win game after game in Spain's colours.
Mourinho has again been at the centre of the storm and refused to speak at last night's press conference at Camp Nou.
He appeared to have got under Guardiola's skin ahead of the first leg last week, but the image of him being held aloft by victorious Real players in Valencia after the Copa del Rey final less than two weeks ago now seems a distant memory. Guardiola was reduced to hitting out and losing his usual decorum, but Mourinho's ranting and red card at the Bernabeu left most Real fans concerned by the conduct of their coach and what they perceived as his negative, defensive tactics at home against Barca.
It is not just the fans. Cristiano Ronaldo was publicly baffled by his coach's insistence that they change their attacking game for a defensive one in which they surrendered possession at home.
Ronaldo has played his part in providing the only genuine highlights from the games. His header which won the Copa del Rey and Real's first trophy in three years was as good as any in his exalted career.
Perhaps the only player who is better than the Portuguese star is Lionel Messi and he added the only other moment of brilliance in the 270-plus minutes of action so far.
The Argentine forward's mazy dribble which led to Barca's second goal in the Bernabeu last week led to another raft of "Is Messi the greatest player ever?" analyses from a salivating global media.
Tonight's game could be the best yet because Real have to attack if they have any hope of overturning a 2-0 defeat to reach the final at Wembley Stadium in London and lift a record 10th European Cup.
Mourinho claims that the tie is over and that his charges have no chance of overcoming Barca away from home, but he is kidding nobody.
"We go to the Camp Nou with the idea to win," Iker Casillas, the Real captain, said. "Everything can happen."
It can, but the last time Real came to Camp Nou and attempted to attack Barca they were hammered 5-0.
Barcelona v Real Madrid match-up
Maxwell v Cristiano Ronaldo
The left-back position is Barcelona’s weakness at the moment with Adriano and Eric Abidal injured. Maxwell, below, is likely to return tonight. Surely, if Real stand any chance, Jose Mourinho must unleash Ronaldo on the Brazilian defender. Let’s not forget that Ronaldo came to prominence with his dribbles down the right wing.
Mourinho admitted that his goal for the first leg was to earn a 0-0 draw which begs the question: how did he plan to gain a win in Camp Nou? With a 2-0 deficit to overcome, Real must attack and Barca are not a team to sit on a lead.
You only need to look back to the three el clasicos in April: a 1-1 draw at the Bernabeu in the league, Real’s 1-0 cup final win and last week’s 2-0 Barca triumph in the Champions League. Real’s last victory away at Barca came in 2007.
At Camp Nou between Barca and Real Madrid
2010/11 Barcelona 5-0 Real
2009/10 Barcelona 1-0 Real
2008/09 Barcelona 2-0 Real
2007/08 Barcelona 0-1 Real
2006/07 Barcelona 3-3 Real
2005/06 Barcelona 1-1 Real
2004/05 Barcelona 3-0 Real
2003/04 Barcelona 1-2 Real
2002/03 Barcelona 0-0 Real
2001/02 Barcelona 1-1 Real
Barcelona (4-3-3) Valdes; Alves, Puyol, Pique, Maxwell; Busquets, Xavi, Iniesta, Keita; Villa, Messi, Pedro
Real Madrid (4-4-2) Casillas; Arbeloa, Abliol, Carvalho, Marcelo; Alonso, Diarra, Ozil, Di Maria; Ronaldo, Higuain
• This is Real’s 22nd semi-final appearance, which is a record. They have won 12.
• Barca have progressed 30 out of the 32 times they won the away first leg in Uefa competitions, including all six in which the away leg finished 2-0 in their favour.