Lionel Messi usually waits until after the match to exchange shirts but American sport stars are not taking any chances amid concerns he could miss Saturday's game in Washington. The Argentina forward, who sat out training on Friday due to a foot problem, has already picked up three jerseys in the US capital, where Argentina are due to play a friendly against El Salvador in front of 50,000 fans at FedEx Field. Lionel Messi was forced to watch from the sidelines as Argentina held a training session on Friday . The Argentina star cut a lonely figure as his team-mates took part in training session at FedEx Field . Messi picked up the foot injury during Barcelona's 2-1 win over Real Madrid on Sunday . Messi had been expected to feature in Saturday's friendly after a scan cleared him to play . First up fittingly was a Wizards shirt after the four-time World Player of the Year  joined his team-mates to watch Wednesday's NBA clash against Indiana Pacers. Then Messi was presented with No 10 jerseys on Friday by Redskins quarterback Robert Griffin III and Capitals forward Alex Ovechkin. 'I'm a big fan, and my wife loves soccer - or football,' Griffin told CSNwashington.com . 'We follow [soccer] all the time and follow the World Cup. I do keep track on these guys, from Messi to Ronaldinho to [Cristiano] Ronaldo. It really is great fun to watch them excel at a sport that I never got to play organised.' The pair watched the Argentina players take part in a training session before meeting Messi the locker room. 'My friend taught me a phrase [in Spanish],' Griffin added. 'I was able to say that to him when I met him. He giggled and said thank you.'
Barcelona forward Lionel Messi was injured during El Clasico on Sunday . Argentina star is in Washington for Saturday's friendly against El Salvador . Messi sat out training on Friday despite an earlier scan clearing him to play .