In a statistical sense, Barca were unfortunate to lose. According to FourFourTwo, they had 29 attempts on goal to Granada's five, which is some difference. When you have Lionel Messi, Neymar, Cesc Fabregas and Andres Iniesta in your ranks, you're entitled to feel that you could score more goals.
"Barca clearly should have won," coach Gerardo Martino said during the post-match press conference. "The result is a shock that happens very occasionally in football."
"We had a good game but lacked any luck," Javier Mascherano told reporters in the post-match interview. Andres Iniesta was equally upset. "We did everything to score but failed to finish," he told Marca (h/t Football Espana).
However, if your team play within a certain ideology and your goalkeeper isn't particularly suited to it—like Jose Pinto—then you should also expect to concede more goals.
Likewise, if you field two natural centre-midfielders in the heart of defence, there are likely to be problems.
Gerardo Martino has got his rotations all wrong in recent weeks. The Argentine made just four changes—one of which was enforced by Gerard Pique's injury—from the team that drew with Atletico in the quarter-final first leg of the Champions League to the home game against the league's bottom club in Real Betis.
Three of those players then dropped back to the bench for the second leg. Understandably, the team as a whole looked tired and lethargic in both matches.
Then, he made three changes to the defence alone as they fell to Granada.
Jordi Alba and Adriano sharing left-back duties is more about giving the Brazilian time on the pitch than it is about resting a key player for important matches. There is nothing wrong with this, but why not make other changes that affect the tempo of the team's passing?
Meanwhile, 34-year-old Xavi is forced to play three games in nine days and then sit on the bench in Andalusia.
Rotating players is an essential part of management at the top level—it's when and how you implement it that makes the difference.
Both Real Madrid and Atletico Madrid had won at Granada by a solitary goal. They played their strongest available teams for the matches and still only came away with narrow victories.
There is an argument that the squad isn't strong enough to deal with resting certain players. How do you preserve Messi or Xavi when there isn't a like-for-like replacement?
That is why Martino and Sporting Director Andoni Zubizarreta take the blame once more for their flawed recruitment policy. The side from the Camp Nou will be denied entry into this summer's transfer market, just when they are in need of a cash injection.
"We deserve a great game for ourselves, to give us joy," suggests Mascherano when talking about Wednesday's Copa del Rey Final.
You have to earn each result individually by not only outplaying the opposition, but crucially scoring more goals than them.
According to AS, some supporters were obviously unhappy and waited for the returning team outside their home ground. "You should be ashamed" and "You’re just thinking about the World Cup" were some of the shouts that could be heard.
Predicting how Barcelona is going to respond is harder than ever. The players are obviously hurt, whilst the coach and fans are looking for a reaction. The real problems come from the squad unbalance, physical tiredness, poor rotation and questionable tactics.
"After two defeats in the Champions League and the League the dressing room feels something important is missing," said Martino.
He never confessed what that might be, if he even knows.