Tottenham midfielder Luka Modric is carrying a knee injury.

"He is excellent, but he has a knee injury that could prevent him playing at the start of the new championship," said Croatia assistant coach Aljosa Asanovic.

"We must keep an eye on him, we have a friendly match with Slovenia on August 20 and then the qualifying matches against Kazakhstan and England in September.

"For these competitive games we need a healthy Modric.

"The injury happened during training, but I believe it is painful more than serious."