By Kilian Caballero
Barcelona approached their last Champions League clash with a new record in sight and the chance to seal qualification for the last 16 as group winners. But defeat at Ajax saw the Catalans miss out on levelling the 21-game unbeaten start to a season made by Pep Guardiola's side in 2011-12 and leaves them still needing a result at home to Celtic on Wednesday to ensure top spot in Group H.
Barca returned to winning ways with a 4-1 victory at Segunda B side Cartagena in the Copa del Rey on Friday night, but back-to-back defeats to Ajax and Athletic Bilbao before that brought a wave of criticism and doubts aplenty. Over-dependent on individuals and with the ideas seemingly still not flowing, Gerardo Martino's men remain under scrutiny.
And with several players missing through injury or suspension, Goal takes a look at the formations available to Martino for Wednesday night's Camp Nou clash against Celtic.
One of the options used by Pep Guardiola in Champions League games for Barcelona and while it may seem somewhat risky, the home team are unlikely to need a fourth defender against a Celtic side who will come and shut up shop at Camp Nou. Many of the Catalans' current problems are also occurring in midfield, so this system would provide more bodies for control of possession and passing combinations in an area where the visitors will be working extremely hard to compete.
This formation, although not associated with Barcelona in recent times, would allow for improved control defensively. Together, Sergio Busquets and Alex Song could provide balance and add stability, allowing more freedom to those in front of them. With this system, Barca could also take better advantage of the spaces available to them at home and cause damage on the counterattack - a tactic Martino has been trying to incorporate in recent times.
THE DIRECT APPROACH
This formation is all about union and association. Akthough not dissimilar to the current system, this approach would see Barca's forwards dropping deeper on the wings to link up better with the midfield against what is likely to be an ultra-defensive Celtic team. With greater link-up play and combinations, Barca could push more midfielders into the box, while the forwards would also be free to take up goalscoring positions in central areas.