The Spanish international has slipped down the pecking order this season, with Zinedine Zidane opting for Martin Odegaard as starter ahead of him.
According to reports from Diario AS, he now wants to leave the Santiago Bernabeu at the end of the campaign, and link back up with former boss Julen Lopetegui in Andalucia.
With his contract in the Spanish capital expiring at the end of the 2021/22 season, Lopetegui is confident of securing a deal in the region of Є20m.
Sevilla were rumoured to be negotiating for a January deal for the former Malaga star, but Zidane blocked their advances, as he wants to keep his full squad together for their title defence in 2021.
Zidane is likely to be very quiet in the January transfer window, with the French coach unlikely to make any major new signings.