By Simon Evans
RIO DE JANEIRO, June 15 (Reuters) - Argentina coach Alejandro Sabella learnt a quick lesson about his team, and his most precious asset Lionel Messi, in Sunday's 2-1 win over Bosnia in Group F - caution won't work.
Sabella surprisingly opted to play an extra defender in Hugo Campagnaro and sacrificed forward Gonzalo Higuain against the World Cup debutants and the result was a flat first half display that belied their status among the tournament favourites.
Admittedly, the pressure was eased on his team after a fortunate third minute own goal from Bosnia defender Sead Kolasinac - the quickest in World Cup history - had given the Argentines the lead.
But with Messi having a limited impact, strike partner Sergio Aguero anonymous and Argentina's midfield looking one-paced and uninspired even against opponents who, in the early stages, looked overawed, it was clear something was not right.
There was simply no reason to have a five-man defence against a Bosnia team that, for all the pre-game talk of taking the game to Argentina, featured Edin Dzeko as a lone striker.
That allowed Argentina to return to the more positive 4-3-3 formation they had fielded through most of their qualifying campaign.
The move did not work straight away - Bosnia had clearly been given an injection of belief by their coach Safet Susic at the break and started the half confidently, creating a couple of opportunities.
But, crucially, with Higuain and Aguero playing as a classic strike pairing, Messi was able to wander deeper into his favourite starting point for his slalom runs at the defence.
Twice the Barcelona forward had attempted to unlock the Bosnia defence with runs from deep and the approach paid off in the 65th minute in spectacular style.
Messi picked the ball up inside Bosnia territory, sprinted towards goal with real intent and then played an intelligent, and perfectly executed, one-two with Higuain before firing home off the post.
It was the kind of goal Barca fans have seen so often from Messi and it should cool some of the overheated talk about his disappointing end of season club form and his lack of goals in the World Cup.
It should also ensure that Sabella is unlikely to keep his trump card in his pocket for the rest of Argentina's campaign.
The team's strength is clearly in their attacking quality and, combining the speed and directness of wide midfielder Angel Di Maria with Messi's threat from deep, they have a potency in attack that would leave most coaches at the tournament envious.
Their next opponents, Iran and Nigeria, offer an opportunity for Sabella to finetune that approach before the knockout stage.
While this was far from Argentina and Messi at their best, they offered enough of a reminder after the break of why many believe they are credible challengers in this tournament. (Reporting by Simon Evans; Editing by Ken Ferris)