Ronaldo has been linked with a move away from the LaLiga winners amid reports he is unhappy at scrutiny of his tax affairs in Spain.
The Portugal international has denied defrauding Spanish tax authorities out of €14.7million in image rights.
Arbeloa, who won two Champions League titles and a LaLiga crown at Madrid and retired in June, said he was sure Ronaldo would stay.
"He is very intelligent. When the perfect moment arrives to speak, he will," he told El Chiringuito TV.