Ronaldo wants out of Real Madrid, nine years after signing from Manchester United in a then world-record £80million transfer deal.
The 33-year-old is understood to be furious at the La Liga giants for their refusal to grant him pay parity with Lionel Messi and Neymar.
Juventus appear to be in pole position to sign Ronaldo, with former club United and Ligue 1 side PSG both cooling their interest.
And Marca suggest Ronaldo’s determination to leave Real may stem from what happened during their Spanish Super Cup showdown with Barcelona last August.
Real Madrid thumped their Catalan rivals 3-1 at the Nou Camp.
Gerard Pique scored an own goal for Barcelona with Messi then equalising from the penalty spot.