Tata Martino will certainly have had his work cut out during training since the debacle of the weekend just passed.
That all of Barca's goals were via mistakes from the away side rather than any modicum of skill from the hosts shows how poorly Barca performed.
Betis even had more shots on goal than their more celebrated opponents, per WhoScored.com.
Against a more prolific front line such as Atleti's, Barca will struggle badly if they cannot get their act together in defence.
Javier Mascherano was like a fish out of water against Betis and will need to step up again against Atleti if Barca are going to have any sort of success in Madrid.
He needs to lead the line and assume the lion's share of responsibility alongside Marc Bartra, who has proved his ability in the role but is still very much learning the trade.
Although there have been some below-par performances in the Barca defence this season, Gerard Pique will still be a big miss for this game.
Alongside Mascherano and Bartra, Jordi Alba could be sacrificed for the more defensively-minded Adriano Correia, whilst Dani Alves will get the chance to show everyone that he can beat Felipe Luis for pace and quality.
The reverse was true in the first leg, Luis playing his part in a fabulous Atleti defensive performance.
Sergio Busquets can be absolved of any blame for the performance against Betis, for he was one of only a few bright sparks. The unsung hero had his name sung at Camp Nou on Saturday with vigor and well deserved it was, too.
Barcelona need the twinkle toes of Andres Iniesta and Xavi Hernandez to be firing on all cylinders. With three of Atleti's midfield on yellow cards and in danger of missing any semi-final should they progress, the midfielders should try to invite some early transgressions to change the dynamic of this one.
Neymar is the only Barcelona player to score against Atleti this season, and he will be given the chance to make it a hat-trick in this game, despite not being in the best form.
Lionel Messi will be looking to add to his tally and the Vicente Calderon holds special memories for him:
Tata's only dilemma is whether he floods the midfield with Cesc Fabregas as the extra man again, or if he goes for broke early and puts in the pacey Pedro Rodriguez to frighten the life out of the Atleti defense.
Who will go through to the semi finals?
His presence is a no brainer if Barcelona want to make their lives easier by going for an early away goal.
Diego Simeone may well try and keep it tight, especially if Diego Costa fails to make the match after his own injury concerns. Atleti simply aren't the same side without having the big man up front to call upon.
But in any event, a goalless draw will do for the Argentinian, as it will see his side progress.
Barca must therefore attack from the very first minute and Tata needs to employ the right tactics, but more importantly, the right personnel to get the result.