Modric has not played for Spurs this summer after he refused to go on the club's pre-season tour of the United States - a move that landed him with a fine.
Modric is desperate to move to Real Madrid, but so far the Spanish champions have not met Tottenham's asking price of just under £40 million. The playmaker will take part in his first game of the summer on Wednesday night when he lines up for Croatia against Switzerland in Split.
His current situation has left Stimac hugely disappointed, with the former West Ham defender accusing Tottenham's chairman of breaking promises to Modric, and of trying to make a name for himself over the saga.
"Daniel Levy promised a year ago that if an offer from Madrid arrived he would let him go. And when the offer arrived he changed his opinion," Stimac told Spanish newspaper AS. "I think that this guy tries to make himself famous in the world of football, but this isn't the way to do it.
"When you promise something you always need to fulfil it. It was the same with (Dimitar) Berbatov before he signed for Manchester United. He went there on August 31."