The 20-year-old made six first-team appearances for Los Blancos during the 2015-16 campaign, before spending last term on loan at Bundesliga outfit Wolfsburg.
Mayoral only managed two goals in 21 appearances for Wolfsburg last season, but the Spain Under-21 international said earlier this month that he was desperate to prove his worth at the Bernabeu.
The striker has not been involved in the first team this season, although Zidane has insisted that the youngster has a role to play during the 2017-18 campaign.
"Mayoral's absence? I don't want another striker. Mayoral hasn't been called up because there's 25 of us and some have to be left out, but I'm counting on him," Zidane told reporters. "It's a year for him to learn and be ready for when he gets a chance to play. His chance will come."
Real Madrid will continue their La Liga season with a home game against Valencia on Saturday night.