A second-string Real Madrid side were held to a 1-1 draw at relegation-threatened Cadiz on Sunday.
With the LaLiga title already wrapped up and a Champions League final against Liverpool at the end of the month, Ancelotti rested a number of first-team regulars.
The LaLiga champions finish off their league campaign next week when they host Real Betis.
"They're difficult games to play. The other team is playing to stay in the First Division," Nacho told Movistar after the game.
"Facing my brother [Cadiz's Alex Fernandez] on a day like today is one of the most difficult games that I've had to experience... On the pitch it's difficult, they're playing to stay up, they have to do it in the last game, so I'll support them and above all my brother."