Messi and Ronaldo go head-to-head in Cup clash
Messi has hit 16 and Ronaldo 12 in their last 10 games, and the four the Argentine got against Osasuna on Sunday makes it 33 in the league while Ronaldo has 21 after his hat-trick against Getafe.
Madrid took the Spanish Super Cup on away goals over two legs and managed a 2-2 draw in Barcelona in the league, the only points Barca have dropped at home, so there is little to choose between the two up to now.
In the league Barca enjoy a 15-point advantage over their rivals but that will all be forgotten when Madrid seek to avenge last season's quarter-final defeat in the same competition that Barca eventually won.
Messi's goals at the weekend meant he became the first player in history to score in 11 consecutive La Liga matches and he can equal or break another record on Wednesday.
One goal would level Alfredo Di Stefano's long-standing 18 goal tally in games between the two sides.
Meanwhile, Ronaldo will be walking a yellow card tightrope.
He has already picked up two in the Cup, another on Wednesday will mean he misses the second-leg scheduled to take place in Barcelona in almost a month's time on the 27th of February.
The Portuguese star also has goalscoring form in recent games with the Catalans, hitting seven in the last six meetings, and he has told his club's TV station that the game can't come quick enough.
"It's an important but complicated game for us against one of the most difficult teams in the world, but it should be a big night. We're at home and have a good chance but we'll have to play well, we know Barca have a great team but I'm looking forward to it," he said.
Real Madrid go into the game with important players missing. Most of all club captain Iker Casillas, who fractured a bone in his hand in the previous round against Valencia.
The club reacted quickly to sign Diego Lopez from Sevilla last Friday as cover, for ?3.5 million, and he will come into contention for his debut.
However, Antonio Adan kept a clean sheet at the weekend with Lopez sat on the bench, and he may continue to deputise.
Also out for Madrid are the suspended trio of Sergio Ramos, Angel Di Maria and Fabio Coentrao, plus the injured Pepe.
Jose Mourinho will have to choose between Raphael Varane, Raul Albiol and former Chelsea defender Ricardo Carvalho for his centre-half partnership.
Mourinho was able to rest Xabi Alonso, Sami Khedira, Karim Benzema and Alvaro Arbeloa on Sunday against Getafe and all should start.
Barca midfielder Sergio Busquets sees the tie being tight despite Madrid missing players.
"It will be an even game, it doesn't matter who is out for them, we must focus on our own game. The tie won't be decided in the Bernabeu so a good result for us would be a win, not a draw," he said.
His side don't share Madrid's selection headaches and key midfielder Xavi Hernandez will be celebrating the signing of a new contract that ties him to the club until 2016, when he will be 36.
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