Prince William Is 'Worried' About King Charles' Return to 'Forward-Facing Duties' Amid Cancer Battle

King Charles recently returned to "forward-facing duties" and sources claim Prince William is concerned about his dad's ability to juggle both his role and cancer treatment.

“He has been frustrated because there is still so much he wants to achieve,” a source said when asked about Charles' reign. "He holds himself to very high standards of public service and genuinely feels he’s letting people and organizations down if he’s not out there doing all those public bits of his formal role."

In February, Charles took a step back from the spotlight to focus on his health, leaving William and Queen Camilla to take over his public duties temporarily.

“He’s a bloody caged lion, driving everyone round the twist if he’s stuck at home," they added.

Although Charles returned to attending engagements on Tuesday, April 30, the Prince of Wales has reservations about it.

“He wants to make sure his father is balancing his recovery," the insider stated. "He knows his dad loves work, but he does worry about him.”

According to an aide, Charles’ diary “will be carefully calibrated with enough downtime so that it is not too draining.”

“Some people might think he is trying to pedal twice as hard because he is conscious that time is running ahead of him, but he’s like that anyway," the aide continued. "His downtime away from public life has been used productively, enabling him to keep thinking about the things he wants to get on with."

Despite Charles' condition, His Majesty continues to remain positive.

“I hear determination that he doesn’t want to let it slow him down, a pragmatic acceptance of the changes that have had to be made to his program, and an absolute desire to get back to full speed," a source revealed.

Aside from Charles' well-being, Kate Middleton will undergo "preventative chemotherapy" and has yet to return to her role.

“There is a huge sense of relief that the family have been given the privacy and peace they asked for," a source explained. "He continues to do his best to try to balance supporting his wife, family and father with his public duty as the Prince of Wales. But of course, from the start of the year, the focus of his family has been at the forefront of his mind.”

Never miss a story — sign up for the OK! newsletter to stay up-to-date on the best of what OK! has to offer. It’s gossip too good to wait for!

In her cancer announcement, the Princess of Wales stressed that "having William by my side is a great source of comfort and reassurance."

Friends of the couple were surprised by the future king's ability to balance his spouse and dad's health and professional responsibilities.

“I don’t know how he managed to keep doing all of that, knowing what he was going through, while the world was ridiculing and throwing shit at his wife while she was having chemotherapy," the source noted. "That speaks to his character, grit and determination to go out there and do the job that is expected of him. He has taken most of it on the chin and got on with it."

Sources spoke to The Times.