The ex-Valencia defender hurt his ankle in the second half of his country’s friendly match against Finland.
It initially looked as though he might be ruled out for some time.
But the £35m signing was able to return to the field and play the rest of his team’s 2-0 win, although he was clearly in some pain.
However, it now looks as though Mustafi is fine and should be in line for his Gunners debut next weekend against Southampton at the Emirates.
Click through the gallery above to see the photos of Mustafi in training.