The Everton attacker complained of high temperature and has been given a break from practice in order to recover in time for his country's final Group C fixture against Spain
The Vatreni sit in second place of Group C at Euro 2012 with four points, and need a victory in their clash against the world champions in order to secure a place in the next round.
According to index.hr, Jelavic, who has started both of Croatia's games at the European Championships, complained of a high temperature and was released from his team's afternoon workout.
The Everton striker is expected to recover in time for the fixture against Spain, however, and has been relieved of his training duties in order to recuperate.
Jelavic is Croatia's second most prolific player at Euro 2012 with one goal from two games.