Swiss prepare for Messi test

Lionel Messi has been the key to Argentina's perfect start at the World Cup, scoring four of their six goals in three straight group wins, and the South Americans hope his blistering form continues when they face Switzerland in the last 16 on Tuesday. Also battling for a place in the quarter-finals are the United States and Belgium, who arrived as one of the favorites to lift the trophy but have not yet fired on all cylinders. Although Argentina have yet to reach the heights many expected of them in Brazil, Messi has been on a different planet, electrifying crowds and banishing memories of the goal drought he endured in South Africa four years ago. Fellow forward Sergio Aguero is a major doubt after picking up an injury against Nigeria in their final group game, however, and should he miss out manager Alejandro Sabella may opt for the versatile Ezequiel Lavezzi. Sabella, though, was playing his cards close to his chest on the eve of the match in Sao Paulo. ‘In case Lavezzi plays he can play in two different positions,’ he told reporters. ‘But I am telling you, the line-up is not decided yet.’ Switzerland hope Xherdan Shaqiri, dubbed the 'Alpine Messi' for his impish skills, will provide the key to beating Argentina for the first time. The bustling little forward has been in top form for the Swiss, stealing the show with a hat-trick in a 3-0 win over Honduras that sealed their spot in the last 16. ‘The midfield will feed him, and he plays really well up front,’ captain Gokhan Inler said of Shaqiri. ‘The good thing is he cannot be figured out that easily. We need to have him free,’ according to Reuters.