Lovren was among the substitutes in Croatia's 1-1 draw in a friendly against Hungary in Budapest on Tuesday night and was told by Cacic to warm up with the rest of the players on the bench.
But the defender decided to end his warm-up early and return to the bench, much to the anger of his coach, who says the former Southampton man has "made a step backwards, away from the squad" after the incident.
"He did not refuse to get on the pitch... because no one invited him to come on," Cacic said, according to Sportske Novosti. "But do you think it is up to Lovren or any other player to decide how long will he warm up? Or is it [the] coach's decision?
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"I will not tolerate such behaviour because no one is more important than the team. Lovren made [a] step backward, away from our squad.
"We didn't talk after the match, we will see what is going to happen, but I will not tolerate such acts and he made [a] wrong move."
Cacic made just one substitution in the draw, as Darijo Srna replaced Mateo Kovacic. Mario Mandzukic opened the scoring for Croatia in the draw, before Balazs Dzsudzsak equalised for the hosts with a free-kick.