Newcastle boss Alan Pardew has been left sweating on the fitness of Fabricio Coloccini after learning that the defender has picked up a knock on international duty.
The Argentina Football Association (AFA) has confirmed that the centre-half is nursing a hamstring problem.
No details as to the severity of the problem have been revealed, but the fact that Coloccini will be remaining with Alejandro Sabella's squad suggests that it may not be as bad as the Magpies fear.
"Fabricio Coloccini has a hamstring injury in the femoral biceps of his right leg," read a statement released on the AFA's official website.
"He will travel with the squad to continue treatment with the team doctor."
It remains to be seen whether Coloccini will be able to play any part in a 2014 World Cup qualifying double-header against Paraguay and Peru.
Pardew, though, will be more concerned about the state in which his 30-year-old captain will be returned to Tyneside.
Newcastle are due to face Everton at Goodison Park on 17th September and have already seen their defensive options severely depleted during the opening weeks of the season.
Ryan Taylor is facing up to a lengthy spell on the sidelines after damaging cruciate knee ligaments, while James Perch missed the 1-1 draw with Aston Villa due to a neck complaint and Danny Simpson limped out of that fixture with a hamstring problem.