Russia will play Croatia at the Fisht Stadium in Sochi on Saturday.

"One of the most important tasks for our team is to contain Modric, because he is a leading player in the Croatian team. [Russia players] need to attack him in order to keep him under constant pressure. He is not young anymore, although he was rested during [his team's] third [group-stage] game," Tarkhanov said.

He added that he did not see consistency in Croatia's game as they "looked good for three games but played worse against Denmark."

During the group stage, Croatia won all three matches, including a 3-0 rout of Argentina, and finished top of Group D, before beating Denmark on penalties in the last 16.

Modric, who is 32, has scored two goals at the World Cup so far and saw his extra-time penalty saved by Denmark goalkeeper Kasper Schmeichel before beating him in the penalty shootout.