At yesterday's announcement of the dismissal of Capello, Mijatovic denied claims that Real had been caught out by free-spending Barcelona since the end of the season.
"We are the most important team in the world. As sport director I must plan the future of the club. With respect to signings, we have a prepared plan and we are advancing on the subject," said Mijatovic.
"In addition, we are not scared of the signings other teams have made. We have a plan."
Mijatovic confirmed the departure of fellow football director Franco Baldini and insisted he had the backing of the club's board.
"It's not true that I've thought about resigning," said Mijatovic. "Capello was questioned by the media and the fans demanded his departure."
Asked about Bernd Schuster as Capello's likely replacement, Mijatovic added: "I know him well and we get along. We don't speak every day, but it's also untrue that we don't get along.
"We are not scared to plan the future with a new trainer, who will reunite everything that we need to take us to success in all competitions. In the future you will see if we are right or not."