The former Madrid sporting director is confident that his compatriot will succeed with the Liga giant and won't be pushed around by his superiors.
The Italian has been described a peacemaker after three years of controversy under Jose Mourinho, but Sacchi has insisted that the former Paris Saint-Germain boss is no pushover.
"Once, before a Champions League game, Silvio Berlusconi said that Filippo Inzaghi ought to start, leading Ancelotti to quip at the press conference: 'Here's hoping the president has got the selection right and we win'," the former Madrid sporting director told Marca.
"The next day he didn't play Inzaghi and they won. He listens to everyone, but he doesn't give in to pressure."
Sacchi then went on to voice his opinion that Ancelotti's teams generally not only get good results, but play attractive football, too.
"I've told him not to forget that winning alone isn't enough in Spain. Carlo is a good, intelligent person who knows football and understands that Real are the most famous club in the world. It's an honor and a source of pride for him, but the same goes for Real Madrid.
"He's a winner as a coach, but his teams don't just get results – they play football the right way, too. When Florentino Perez asked me about him, I told him he shouldn't think twice about signing Carlo."
Ancelotti signed a three-year deal with Madrid last week.