Arsenal midfielder, Declan Rice, has not travelled for their Champions League clash at Inter Milan on Wednesday.
Rice was not spotted in training alongside his teammates on Tuesday and there has been no official statement from the club.
The England midfielder played all 90 minutes, as the Gunners lost 1-0 last weekend.
This development will mean that Mikel Arteta is set to juggle his midfield options again.
But Arteta will have captain Martin Odegaard available for selection again after two months out with an ankle injury.
Arsenal have won two and drawn one in their first three fixtures in the Champions League.