Trauma and illness have thinned out the Russian national team, leaving only 17 players ready to represent their country in Wednesday's match against Portugal.
Right-back Andrej Karjak has become the latest to drop out of the lineup before the 3rd World Cup qualifying group match in Lisbon.
"Andrej fell ill with the flu, with the possibility of sinusitis not ruled out," said team doctor Yuri Vasilkovas, as quoted in the Russian press.
The Russians, who crushed Luxembourg 4-0 on Saturday, were already missing five players, including the main national team goalkeeper Sergei Ovchinnikov, who is suffering from various injuries.
Kazan goalkeeper Denis Boyarintsev, who improved Russia's attack in the second half of Saturday's match, replacing debutant Lyubomir Kantonistov on the field, will most likely take over Andrej Karjak's position on the left flank on Wednesday.
The match in Lisbon now holds much greater importance for both teams, especially after Euro 2004 finalists Portugal played to a surprising 2-2 draw with European minnows Liechtenstein on Saturday.
The Russians also dropped points after drawing at home with Slovakia in the first qualifying match last month.
Slovakia leads the group with 10 points from four matches. Portugal has seven points and one match in hand. Russia has four points from two matches.