Former Manly-Warringah Sea Eagles halfback and ABC Sport rugby league commentator John Gibbs has been diagnosed with cancer.

Gibbs, 70, has been part of the ABC Sport team since 2016 and has been a popular personality among listeners.

He was on the ABC Sport call with Andrew Moore and Matthew Elliott on Sunday afternoon when the Parramatta Eels defeated Wests Tigers.

"Gibbsy", who played 81 first grade games for the Sea Eagles and represented New South Wales and Australia, announced his diagnosis on Monday, and that he would be stepping away from broadcasting to focus on his health.

Moore, ABC Sport's lead rugby league caller, said his friend Gibbs wanted listeners to know he was prepared for his upcoming treatment on NRL MONDAY.

"John Gibbs called me this afternoon to confirm something he had been fearing for a while. He's been diagnosed with cancer — Hodgkin's lymphoma," Moore said.

"He knows he's in for a fight, but he wants you to know he's up for it.

"We are family and, as I discovered a year ago, the wave of support from the ABC team, it's significant, it's powerful, it's amazing and it helps.

"Like so many of you, he's ready to kick cancer to the kerb and beat the mongrel."

The former international has been a constant on Sydney radio since the 1980s as a commentator, presenter, and host for 2UE, 2GB and ABC Sport.