Diego Costa will be looking to shine
If Diego Simeone’s side can beat their city rivals—and, this season, their title rivals—it will be the first time they have ever won three games running against Real.
He has already made history by taking them to the top of La Liga, breaking Barcelona’s record stint at Spanish football’s peak, and will be relishing the battle against Carlo Ancelotti’s side.
Barcelona, meanwhile, are firm favourites to see off the Basque club who haven’t reached a Copa del Rey final since 1988.
Sociedad have struggled on the road too, whereas the Blaugrana are strong at home.
At least until Valencia’s triumph there on Saturday.
That Barcelona defeat will give Jagoba Arrasate some hope, as his men prepare for their Camp Nou trip.
Here, we take a look at five things to look out for in these semi-finals.
Dangerman: Antoine Griezmann is a distinct threat
Outside of anyone playing for La Liga’s three title contenders, Antoine Griezmann is the form player in Spain.
The French winger, who helped Sociedad qualify for this year’s Champions League by scoring the only goal of the game against Deportivo on the final day of last season, has been in fine fettle.
Griezmann has 13 goals in his last 14 Liga matches and will be looking forward to exposing any holes in Barcelona’s defence.
And there are plenty to be found.
He is whippet-quick and showed that with a brilliant sprint against Elche to beat the goalkeeper to the ball, before lofting it over him and towards the goal.
Damian Suarez ran back to the goal-line to try and clear it, but only succeeded in smashing it off the crossbar, off himself and into the net, meaning it went down as an own goal.
Bring it on: All eyes will be on Diego Costa
When the former Barcelona striker features, Costa sometimes has to accommodate him by making wider runs and doing a lot of leg work.
Jose Mourinho will be interested in watching his transfer target performing in pole position.
He’ll also be keeping tabs on how Thibaut Courtois performs, in light of the news, reported by Sky Sports here, that he is likely to be back at Chelsea next season.
One more big performance may be enough to convince Mourinho to ditch Petr Cech in favour of the young Belgian.
Another chance? Bartra played in the last Copa game
Tata Martino could bring in youngsters Marc Bartra and Martin Montoya as he tries to fix the leaky defence which saw Barcelona ship three soft goals to Valencia at the weekend.
There has been a clamour for those two players to get more opportunities, with Gerard Pique off colour and the combination of Dani Alves and Jordi Alba in the full-back slots arguably too aggressive.
Blaugrana fans would love those two to come into the side and impress Martino enough to keep them on for the league game against Sevilla on Sunday and beyond.
With high-scoring Manchester City in the Champions League approaching, the defence is an increasing worry.
Chelsea managed to keep them quiet on Monday night, but the Blues have the players to do it—a combination of power in defence and speed in the transition between defence and attack.
Getting testy: Cristiano Ronaldo will be provoked
Having been sent off against Athletic Bilbao, somewhat harshly in his opinion, Cristiano Ronaldo may take to the field with some anger in his veins.
Normally that spells trouble for his opponents, but Atletico may try to use it against the Portugal striker.
Carlo Ancelotti confirmed that he would be starting Ronaldo, as reported by the BBC.
The last time Ronaldo took on Atletico in the Copa del Rey he was sent off, again on a marginal call, during last year’s final.
Atletico won that 2-1 after extra-time, even though it was hosted at the Santiago Bernabeu, ending their 17-year trophy drought.
Improvement needed: Tata needs to get his squad in shape
Barcelona are in what Madrid manager Carlo Ancelotti would call a “bad moment”, having finally been deposed at the top of La Liga, with an off-colour Lionel Messi and an absent Neymar.
Tata Martino needs to inspire his men to come out of their stupor, but his words on Tuesday seemed uncomfortable.
He was quoted by InsideSpanishFootball.com as saying:
I think that when an opponent starts to grow in a game because of your own mistakes, then there are doubts. The confusion began because of doubts that originated tactically. From the day I arrived at Barcelona, right up to today, it [pressure] doesn’t affect me. The pressure every day is the same and right until my time at Barcelona ends, it will remain the same way.
He seems to be admitting tactical errors for the previous defeat and even mentioning the end of his reign is ill-advised as it invites people to think about a Barca post-Tata.
It will be interesting to see how his team react to the weekend's defeat.