Republic of Ireland boss Martin O’Neill revealed that Seamus Coleman has suffered a stress fracture in his foot.
O'Neill was also full of praise for his non-playing captain, who was ruled out of the friendly international draw with Poland but still travelled with the group.
The manager remains hopeful that his "inspirational" skipper will be fit and available for the two vital games coming up next month against Denmark and Wales in the Nations League.
"Seamus went for a scan, he has a little stress fracture, which is a concern," O'Neill told RTÉ Sport.
"He could easily have got a flight home, but he stayed with the team.
"He is a great captain, a really great captain. He is inspirational and obviously we hope he is back in time for the games coming up."