It didn't take long for 2012 to throw another Clasico into an extraordinary run of matches between Spain's two richest clubs, which has seen Pep Guardiola and Jose Mourinho face off eight times in a season and a half. The score stands at Barca 4, Real 1, with three ties. That sole victory is what Mourinho is defending in the Bernabeu tonight, the King's Cup, a competition in which Real and Barca have met relatively infrequently. This will be the fifth quarterfinal meeting between the clubs, with both having won two of the previous encounters each. It also presents a curious chance for Barcelona to level the historical tally with perfect symmetry. In 216 matches in all competitions, Real has won 86 and Barca 85, with 45 ties. In the cup, though, Barcelona has not won in Madrid since 1968. For Guardiola, who turns 41 today, the match is an opportunity for yet another footnote in the record books. If Barca avoids defeat, it will become the first side ever to go seven games unbeaten in the Bernabeu.

Real looks stronger going into the match, having won 22 of its past 23 matches in all competitions, while Barcelona over the same period has dropped points at Sevilla, Athletic, Getafe and Espanyol. Guardiola admitted last week that Barca's away form has to improve if it is to retain its Liga crown for a fourth consecutive year. The cup may be the least important competition on the two sides' agenda, but as Xavi pointed out, whichever comes out of the two-leg tie victorious will have a huge boost of confidence for the rest of the season -- and for a potential three more Clasicos.

Three players who could be key to the game:

Jose Manuel Pinto

The occasional Barcelona goalkeeper is nicknamed "Tao Pai Pai" after a character from something called "Dragon Ball." Pinto probably sees about as much of that sort of ball as he does the other at Barcelona, due to the remarkable durability of Victor Valdes. However, Guardiola always plays Pinto in the cup and said this week it would be "treasonous" not to do so simply because Real is on the other side of the halfway line.

An online poll of Barca fans did not concur, the main argument against Pinto being that he was between the sticks for Guardiola's sole loss against Madrid in last year's cup final. In fairness, it's unlikely that either Valdes, Iker Casillas or some hybrid of the two would have stopped Cristiano Ronaldo's header, but Barca fans are a superstitious lot. It is easy to forget that Pinto was once a first-choice keeper, and won the Zamora Trophy in 2006, at Celta, and even Casillas has just one Zamora to his name. "He's a great goalie, and nobody who knows him doubts that," Guardiola said. "We certainly do not, and those who have seen him in action these past few years know that he has always played at a very good level."

Jose Callejon

"I like his mentality," said Mourinho of Callejon recently. Signed from Espanyol in the summer, the winger/forward did not exactly set pulses racing in the capital. A former Real youth player, it was broadly anticipated that he would follow the Esteban Granero/Pedro Leon school of returning alumni and drift quietly into obscurity. But Callejon has delighted the Bernabeu with his tireless running, 10 goals in all competitions and by looking like he means it when he points to the badge and smiles. He's also the most effective goal scorer in the league. His winner against Mallorca last weekend brought his league tally to three, with four in Europe and three more in the cup, scored at a rate of one every 75 minutes. Lionel Messi finds the net every 76 minutes, Gonzalo Higuain every 80 minutes, Cristiano Ronaldo every 91 and Karim Benzema every 101.

Cristiano Ronaldo

Open can, release worms. Everybody knows Ronaldo is a great player -- no one more than Ronaldo himself -- but he really needs a good performance against Barcelona to convince the Bernabeu of it. Some sections of the crowd have taken to booing the Portuguese after his lackluster display in Real's 1-3 league loss to the Catalans, and Ronaldo has responded in kind by sulking, taking pot shots from 40 yards and refusing to celebrate a meaningless fifth goal in a routine 5-1 win over Granada. Messi, in the 10 Clasicos contested since Ronaldo joined Real, has scored seven times. He has bagged 13 in all the Clasicos he has played in. More notably, the Argentine's goals-per-minutes ratio against Real is practically the same as against any other opposition. Ronaldo has scored just three in 10 Clasicos, well below his usual strike rate, and wasted two gilt-edged opportunities in December's league match. After that game, when the catcalls began and the media bared its claws, Ronaldo bagged a hat-trick against Sevilla. "This should serve to shut a few mouths," he said afterward. It didn't. But a similar return against the eternal rival most certainly would.