Russia midfielder Yuri Zhirkov has a suspected calf muscle tendon inflammation, the Russian national football team said on Monday.
"He [Zhirkov] has a suspected calf muscle tendon inflammation. Today the player will undergo additional examination that will determine the further tactics and the treatment duration," the team said via their official Twitter account.
The 34-year-old was substituted at half time as his side beat Spain on penalties to reach their first-ever World Cup quarter-finals on Sunday. Russia head coach Stanislav Cherchesov said after the match that Zhirkov was almost certain to play no further part in the World Cup.