Turkey defender Emre Gungor will miss the rest of Euro 2008 due to a calf injury.
Gungor suffered the problem in the thrilling 3-2 win over Czech Republic on Sunday which booked the Turks' place in the quarter-finals.
The Galatasaray stopper was replaced just past the hour mark against the Czechs on only his second international appearance.
His absence merely compounds Turkey coach Fatih Terim's selection problems ahead of Friday's quarter-final against Croatia.
Terim is already without Volkar Demirel, Mehmet Aurelio and Tumer Metin for the game in Vienna, while Servet Cetin is also a concern.
Demirel and Aurelio are suspended for the last-eight showdown, while Metin has failed to recover from a groin injury.
A decision on Cetin's participation will be left to the player, who has been battling on despite knee and hip injuries.
Semih Senturk and Nihat Kahveci are expected to shake off knocks to feature against Croatia, and captain Emre Belozoglu could also return after a groin complaint.