He has found a strong niche for himself in the heart of Croatia's engine-room and will be a major key in how the Eastern European side perform.
German born and based, he has spent most of his career in the Bundesliga with Bayern Munich and, before that, Hamburg and Bayer Leverkusen.
He covers large areas of the pitch in every game and acts as a strong provider for the players around him.
Kovac's versatility ought to provide coach Mirko Jozic with further options.
Niko is Robert Kovac's elder brother.