Germany forward Mario Gotze could be out until the end of the year with a groin injury he picked up in the loss to the Republic of Ireland.
The German football federation says the Bayern Munich player is expected to be out for 10 to 12 weeks after being subbed off in the first half of the Aviva Stadium defeat.
Gotze, 23, will be treated initially by the DFB's medical staff in Leipzig, where Germany plays its final European Championship qualifier against Georgia on Sunday.
"Mario suffered a tendon tear in the abductor muscle while making a lunge," said Germany team doctor Hans-Wilhelm Mueller-Wohlfahrt.
"We wish him a good recovery - I'm certain he'll be back to his good form again," added Germany coach Joachim Low.
Gotze's injury rules him out of the remaining Champions League group stage games, with Arsenal up next for Bayern Munich at the Emirates Stadium on October 20.
Gotze has made seven appearances for Pep Guardiola's side in the Bundesliga, scoring one goal, and his absence may open up opportunities for Kingsley Coman.
The Bavarian club have started the season in perfect form, with 10 wins from 10 games across the Bundesliga and Champions League.
As for Germany, Low's side need a draw against Georgia to make sure of automatic qualification for Euro 2016.