Lionel Messi looks set to miss a second friendly with Argentina this week due to a "mystery" injury in his right foot.
Messi sat out his country's 2-0 friendly win over El Salvador in Washington DC last Saturday, and now seems unlikely to play in Tuesday's game against Ecuador in New Jersey due to a problem which national coach Gerardo Martino says causes pain whenever he puts on his boots.
The issue has raised alarm bells back in Barcelona, where the superstar had showed no signs of injury during recent outstanding performances in La Liga and the Champions League.
Mundo Deportivo reports claims in Argentina that the "mysterious" problem was picked up during the recent 2-1 Clasico win over Real Madrid, and worsened over his first few days with the national squad last week.
The Albiceleste coach told his pregame news conference that no final decision had yet been made over whether Messi could play against Ecuador, but there was no need to take any risks in the friendly game.
"[Messi] is comfortable in runners, but it hurts when he puts on his boots," ex-Barca coach Martino said. "We will see if he can play or not. He is not ruled out. But there is no need to take risks with Leo, or with anyone. It would be unforgivable, having the reports, not to be prudent."
Messi is expected back in Catalonia later this week, with the Liga leaders in action on Sunday evening at Celta Vigo.