The Real Madrid boss says that he would look to strengthen other positions in the squad rather than acquiring the Barcelona star were he able to recruit any player
The Portuguese has received widespread acclaim for his performances this season, including a stunning hat-trick for his country in the second leg of their World Cup play-off with Sweden, which sealed their place at Brazil 2014.
The 28-year-old, who has also excelled at club level, is a firm favourite to lift the Ballon d'Or in January and Ancelotti says that, were he given carte blanche to recruit any player he liked, he would strengthen in other positions rather than bring the Argentine to the Santiago Bernabeu.
"If I could sign one player for Real Madrid, it wouldn't be Messi, I'd rather reinforce another position," he told Radio Capital.
"We have Cristiano, who needs Messi? God gave [Ronaldo] a special gift."
However, Ancelotti did joke that Los Blancos might be interested in bringing Messi to the club should Barca decide to sell the Argentine.
He added: "If Barca sell Messi, they should call us."