Modric has been the subject of intense transfer speculation this summer, but as of yet no club have reached the £40 million asking price Spurs are demanding for his signature.
Modric refused to travel to the United States for Spurs' tour and has not been picked for any of the club's other pre-season games since.
That has not gone down well with national head coach Stimac, who plans to give the 26-year-old his first game of the summer on Wednesday when Croatia face Switzerland in Split.
"I don't like the situation that he is in at all, he has not played any matches at all this summer," Stimac was quoted as saying on AS.com.
The former West Ham defender said he is confident the player will leave White Hart before the end of the month, however, adding: "He will end up signing for Madrid before the market shuts."