Food poisoning forced Russia right-back Roman Shishkin to skip training for a second-straight day on Wednesday as the team prepares for Friday's friendly against Uruguay.
The Lokomotiv Moscow defender, 25, has traditionally played second fiddle to Zenit right-back Alexander Anyukov in the national team, but his reliability makes him a useful member of Dick Advocaat's Euro 2012 squad.
The team's pre-tournament training camp began this week for Advocaat's 26-man provisional squad, with Shishkin the only concern.
"Shishkin has the same problem as he had before," Advocaat said Wednesday, referring to a food poisoning case Shishkin came down with on Tuesday.
Russia play Uruguay on Friday at the Lokomotiv Stadium, ahead of a second friendly against Lithuania on Tuesday and a third against Italy on June 1.
Shishkin has won eight caps for Russia, making his debut in a 2-0 win over Estonia in 2007.
He has three goals in 56 appearances for Lokomotiv.