ABC radio commentator Andrew Moore suffered a heart attack last year and later made a full recovery.
Anthony Maroon, 60, also suffered a heart attack last weekend and was hospitalised.
He had been due to call Australia's opening Rugby League World Cup game against New Zealand for Triple M.
The League Scene social media account posted: "Sending the love to broadcaster Anthony Maroon who suffered a heart attack last weekend."
Maroon is now home and in good spirits, with hopes he will return to broadcasting soon.
One supporter wrote: "Horrible news! Love Maroon. Was wondering why he wasn't commentating the RLWC."
Maroon hosts Triple M's Rush Hour with Nathan Hindmarsh, Millie Elliott and Adam Peacock, and calls weekly NRL games.
He is known for his distinctive voice and is regarded as a fit, health-conscious broadcaster.
Other health challenges have affected the NRL radio community.
In August this year, Johnny Gibbs said he was leaving his ABC role after being diagnosed with Hodgkin's lymphoma.
Darryl Brohman left 2GB last November and announced in June that he was cancer free.