The Spain international told Cadena Ser (via Goal's Sacha Pisani) he rates Neymar, 25, as one of the best players in the world and would be happy to welcome him to Real:
"I like to have the best and it's clear Neymar is one of them. Maybe it was easier for him to go to PSG, instead of directly to Real Madrid. They are personal decisions, you never know what can happen because football goes around a lot. I already have the door open for him if he wants to come. I also have a good relationship with him."
On the pitch Neymar has enjoyed a stellar start to life at PSG since his shock £200 million move from Barca to the Parc des Princes in the summer.
He has netted 11 goals and provided seven assists in a combined 12 appearances in Ligue 1 and the UEFA Champions League as PSG have gone unbeaten so far in 2017-18, per WhoScored.com.
However, recent reports have indicated Neymar's relationship with manager Unai Emery is deteriorating, while the former Santos man has reportedly been underwhelmed by the quality of opposition PSG face in Ligue 1, per Sport's Joaquim Piera.
Meanwhile, Neymar's father has reportedly met with Real president Florentino Perez to discuss the potential of his son eventually replacing Cristiano Ronaldo at the Bernabeu, per Mundo Deportivo's Francesc Aguilar (h/t MailOnline's Matt Maltby).
Neymar's world-record move to PSG from Barca in the summer was one of the most startling transfers in recent history.
He was part of arguably the best attacking trio in the world, with Lionel Messi and Luis Suarez, and had won two La Liga titles, a Champions League and the Copa del Rey three times in just four seasons at the Camp Nou.
However, it seems as though the switch to Paris is not working out for Neymar as he had planned, and he may yet shock the world again by returning to Spain to join Real.