Prince Charles was summoned by Prince Philip to the hospital where the Duke of Edinburg is being treated.
Days after the Prince of Wales visited the hospital treating his father, a royal expert said he was requested to visit the medical facility.
Commenting on his visit, a royal expert said Prince Philip could have requested Prince Charles visit him in hospital for urgent talks.
Ex-royal press secretary Dickie Arbiter, while talking the Royal Beat on True Royalty TV, said, "I think it was at the request of the Duke that the Prince of Wales visited".
He added, "To lay the ground. Look the man is 99, he is in with an infection. "My guess is that he will come out, he will walk out and he will go back to Windsor.
Mr Arbiter said, "But eventually he is going to die and he was just saying to Charles, 'one day you are going to be the leading man of the family'."