Danger!!! Reasons why Barca MUST buy a defender.

Ruthless defending is not the style in Spain. Rather than sit deep and allow the opposition attack, Spanish teams retain the ball for long spells virtually making the other team run all day. Barcelona are the masters of this craft and has worked for them brilliantly until recently.
                    
Under Guardiola, Barcelona created a system that was effective and brutal. Keep the ball throughout and when the opposition do get the ball, they are chased in packs, harrying them off the ball or forcing them to make mistakes. The ball was usually won back in midfield so the defenders maintained a high-line, practically pushing the play to the oppostion's half. To ensure the system worked everybody played a role defensively, working hard to retain the ball. It was like a crime to have the ball against them, Most teams usually just give up possession. Brilliant system!!. But that was when it worked, I have always had a saying -  A team's defence is only as good as the opposition attack allows it to be.
                           
This means if a team's defence isn't under pressure, it looks like a solid impenetrable wall. Last season showed otherwise for the Catalans. While under Guardiola they marked in numbers, under Tito they were lax and lazy and the like's of Messi and Pedro didn't fall back quite like before. Xavi nursed an injury most of last season so his contribution was limited defensively. That meant the only person screening the defence, Sergio Busquets, had to work doubly hard but he himself is not a born ball winner and gets caught out way to often.
                          
Once the midfield collapsed, cracks appeared all over the defence. Carles Puyol aka Captain Caveman is not the defender of three or four years back. He is slower and more of a suspect than ever. Gerard Pique is good not fantastic but needs a solid partner becuase he himself is error prone. Looking for Shakira in the stands doesn't help either. Daniel Alves is still Daniel Alves but pushes way too up the field and gets caught quite often. So also Jordi Alba. Javier Mascherano is a good alternative but he was never a defender and looks uncomfortable in that position.Marc Batra is promising but way too inexperienced for the big leagues.
                            
Against Bayern, they suffered. The German's took full advantage of their fragile defence and tore into it repeatedly. It was embarrassing to watch!!! In other for Barcelona to avoid another 7-0 humiliation, new boss Gerardo Martino must demand a new centre back.
                             
Thiago Silva was their number 1 target but he has committed to PSG. Chelsea are unprepared to sell David Luiz. Liverpool recently stated Martin Skrtel is availiable and he is solid and can plug the leaks in Barce's defence. Either way Barce can't risk a another season without a new centre back. They paid for it dearly last season. I'm afraid 7 UP may occur again if they don't.