Soccer-Four key battles in Netherlands v Argentina World Cup semi-final

By Simon Evans SAO PAULO, July 8 (Reuters) - Here are four key battles in the World Cup semi-final between Netherlands and Argentina at the Corinthians arena on Wednesday. Netherlands winger Arjen Robben v Argentina full back Marcos Rojo: Stopping Robben will be the main task for the South Americans and will require much more than the efforts of Rojo. But the Sporting Lisbon defender will have a key role in limiting the effectiveness of the Bayern man on the Dutch right. The problem for Argentina is that Robben has been used smartly by Dutch coach Louis van Gaal in different roles and has frequently attacked from central positions. That will raise the question of whether Rojo follows him into the middle, which risks leaving the flank clear for Dirk Kuyt to attack from his deeper role on the right or whether a midfielder is given the task of picking up Robben. With Robben famed for his ability to cut in from the right on to his favoured left foot, Rojo, who has had an impressive tournament and returns after missing the quarter-final win over Belgium due to suspension, will also need help from his central defenders. Keeping Robben quiet will be a team effort. Netherlands midfielder Wesley Sneijder v Argentina midfielder Javier Mascherano: Sneijder had been written off as a top-flight international player after a poor Euro 2012 but he has re-emerged in this tournament and is clearly relishing the attacking role given to him by Van Gaal. The Galatasaray midfielder has become the main source of forward surges from the Dutch and if he can get control of the centre of the park it could have a major impact on the game. Mascherano has been used mostly as a central defender in recent times by his club Barcelona but has shown in Brazil that he can still play the defensive midfield role as well as anyone in the world. Limiting Sneijder's influence will be a key part of his job. Argentina forward Lionel Messi v Netherlands defensive midfielder Daley Blind: If ever there was an example of how modern football is not about one defender marking one forward it will be displayed in how the Dutch cope with Messi. But with the Argentine increasingly operating in a deeper role, it may well fall for Blind to limit his impact. Messi has been at his most dangerous in this tournament when dribbling from deep and with the Dutch central defence keeping close tabs on Gonzalo Higuain, it could be Blind, with help from Bruno Martins Indi, who has to work on making sure Messi is kept away from the penalty area as much as possible. Netherlands striker Robin van Persie v Argentina defender Martin Demichelis: A Manchester Derby in the World Cup semi-final with United's forward up against City's centre half. Van Persie has been kept quiet in the knock-out stage of the tournament but, if he recovers from his pre-match sickness, he should spearhead the Dutch attack. Demichelis enjoys an old-fashioned man-marking job and could well have the task of making sure that the Dutchman does not get an opportunity to display his lethal finishing. (Editing by Ed Osmond)