Ukraine coach Oleg Blokhin has revealed that the Euro 2012 co-hosts were missing 10 players due to a stomach upset in their 2-0 defeat to Turkey on Tuesday evening in Germany.
Caner Erkin and Mustafa Pektemek scored to hand the Turks victory, with Blokhin left worrying about the health of his players ahead of their opening match against Sweden in Kiev on Monday.
Key midfielder Anatoliy Tymoshchuk is currently in hospital and on a drip due to the illness that has also affected striker Andriy Voronin.
"Tymoshchuk is still in a bad condition, we have got him on a drip," Blokhin told reporters following the defeat.
"And this is not funny. We have to wait for the doctors' verdict but the situation is far from funny.
"I do not know the reason for the illness because we all ate different food. We have one week to recover ... it's good that it did not happen on June 11 [when Ukraine play Sweden]."
Defender Bohdan Butko and midfielder Denys Garmash were among those ill, Blokhin confirmed, but agreed to play through the pain barrier so that Ukraine could complete the fixture.
"If Butko and Garmash refused to play I could have cancelled the game because of a lack of players," Blokhin admitted.
Blokhin used five substitutes during the fixture, including captain Andriy Shevchenko, with both Butko and Garmash featuring from the start.