The 55-year-old Chilean was installed on Tuesday as Real's 12th coach in 11 years and will be charged with making the spectacular sporting project promised by new president Florentino Perez into reality on the pitch.
At Villarreal, where Pellegrini's sole piece of silverware in five seasons was an Intertoto Cup in 2004, he was closer to an English-style manager, with a good deal of influence over the buying and selling of players.
Villarreal's board backed him over Juan Roman Riquelme when the pair fell out in 2007 and the Argentina midfielder was soon on his way to Boca Juniors.
Next come former player Miguel Pardeza, who has replaced Predrag Mijatovic as sporting director, and Zinedine Zidane, one of the "galacticos" Perez brought in at huge expense during his first term, will be a special adviser to the president.
Some in the Spanish sports press have said Pellegrini's contract of only two years suggests he is an interim solution rather than a long-term one and will eventually be replaced by a bigger-name coach.
Asked by Reuters at a news conference on Tuesday how much decision-making power he would have at Real compared with Villarreal, Pellegrini said: "Exactly the same."
"Big clubs are always required to win every Sunday and it's difficult to keep a project going if that's not happening," he said. "But usually those that have a long-term project and know how to keep it going are those that get the best results."
Perhaps Pellegrini's most demanding, and least patient, master will be the fans in the Bernebeu.
