"FC Shakhtar and FC Anzhi reached an agreement regarding Willian's move to the Russian club in a transfer worth 35 million euros," Shakhtar said in a statement.
"We wish our former player success in his new team."
Big-spending Anzhi are second in the Russian top-flight, two points behind leaders CSKA Moscow.
"FC Shakhtar and FC Anzhi reached an agreement regarding Willian's move to the Russian club in a transfer worth 35 million euros," Shakhtar said in a statement.