Andrea Pirlo credited Carlo Ancelotti with helping him become the player he is today.
Pirlo spent eight years playing for Ancelotti at AC Milan.
Real Madrid and Juventus begin their Champions League tie this week.
"It's like rediscovering your father again," Pirlo told La Gazzetta dello Sport. "He changed my career, putting me in front of the defense. We shared some unforgettable moments. We had a magnificent past together."