Zlatko Junuzovic has been ruled out of Austria's Euro 2016 meeting with Portugal on Saturday due to an ankle injury.
Marcel Koller's men came into their Group F opener as favourites to beat Hungary, but suffered a disappointing start to the tournament by losing 2-0 in Bordeaux.
"Zlatko has a partial tear of the outer band of the right ankle," said Austria team doctor Richard Eggenhofer.
"The main focus is now placed on conducting therapies to reduce swelling. He gets ice therapy, compression bandaging and special enzymes. Zlatko is treated by the medical department virtually around the clock.
"Such an injury is always to judge by the day or by the hour - an accurate prediction of the healing process is difficult. With any luck, we'll get him for a possible second-round game, ideally, a bit earlier."
"Of course it is very bitter," said Junuzovic. "From the 15th minute it was more or less an ordeal. I tried to play with it, but I was in great pain.
"Currently, my mood is very depressed, but that is the way it is. We have to see that we get off the swelling. We still have two matches. I believe in the guys, and that we will get there. Anything is possible and I will do everything that I can."
