The agent of Iker Casillas has suggested that Cristiano Ronaldo could be the next high-profile departure from Real Madrid.

The 30-year-old superstar signed a lucrative six-year image rights deal with Mint Media last month - a company owned by Valencia owner Peter Lim.

Consequently, Santos Marquez says that such a deal can only harm the Blancos in the long run and claims it is an indicator that all is not right between Ronaldo and president Florentino Perez.

"One day [Perez] will need to explain why Cristiano works for another company outside of Real Madrid," the agent told AS.

"Imagine Cristiano generating €40m (£27.9m) elsewhere and giving it to Peter Lim, Valencia's owner. It ends up in Valencia's coffers and that's deplorable.

"Will anyone speak out and ask Florentino why Cristiano has sold his image rights to Peter Lim? That's not normal; it suggests that Cristiano is planning to leave."

Marquez's comments came in a lengthy interview in which he slammed Perez over forcing his client to join Porto after 16 years in the Blancos' first team.

Casillas, who first joined the club at the age of nine, broke down in tears during his farewell press conference last week.

The Ballon d'Or holder Ronaldo is contracted to the Santiago Bernabeu club until 2018.