The Italian rates him as one of the best young midfielders in the world alongside Isco and Paris Saint-Germain star Marco Verratti
The 20-year-old has become an increasingly key man for the Serie A champions following his move from Manchester United in 2012, having played in all but one of his side's league games this season.
The France international has been strongly linked with Ligue 1 champions Paris Saint-Germain as well as a move back to Old Trafford, but Madrid now appear to have entered the race.
"He is a very good player," Ancelotti told RMC Sport. "He has a very good future. He is at a big club and is doing a very good job.
"He is a complete midfielder. Get him? Why not. This is one of the best young midfielders alongside [Marco] Verratti and Isco."