The weekend prior to international fixtures is a nervous time for the national team coaches. They wait apprehensively to see if their players have come through unscathed and are given the green light by their respective clubs. Maybe the odd pulled muscle, cramp or such like is occasionally exagerated by the club sides? Who knows. If that is the case who can really blame them, after all it's not the FA's who pay these guys salaries and transfer fees. Now that revenue seems to be the major driving force behind the club game an injury to a 'crack' in an apparently meaningless friendly could have major consequences.
To avoid any future 'will he or wont he play' shenanigans or any potential injury Barcelona have devised unique new approach: Lionel Messi will only play friendly matches when Barcelona say he can. This proposal is not quite as surprising as it first appears. The pre-Olympics tug of war between the AFA and Barcelona meant that Messi could travel to Beijing. However Barca only agreed to release the player on the understanding that they could refuse call-ups for friendly games. A Catalan delegation are in Argentina this week to see if the AFA are as good as their word in an effort to try to make the agreement more formal.
Personally I wouldn't cross the street to watch an international friendly nowadays. Even the commentators struggle to keep-up with the constant substitutions in the 2nd half. Argentina's next international friendly is against Scotland in Glasgow on November 19th and I suspect many tickets will have been sold for this game in anticipation of Messi playing.