North Melbourne star Ben Cunnington has had a setback in his cancer battle and needs a nine-week course of chemotherapy.
But the AFL club says the midfielder is expected to make a full recovery.
The Kangaroos said in a statement on Saturday that a routine post-surgery check had detected a secondary cancer.
One of North's most popular players, Cunnington had surgery in July for a testicular tumour.
In August, Carlton co-captain Sam Docherty also needed chemotherapy after a secondary cancer was discovered.
Like Cunnington, the setback came after Docherty had surgery late last year for testicular cancer.
The dual club best and fairest winner has played 227 games for North since his 2010 AFL debut.
He managed 19 games this season, but was diagnosed with cancer in July and had to stop playing after round 19 because of his operation.
Cunnington finished runner-up in the club best and fairest voting and made an emotional speech at the online event in early October.
Never noted for his public speaking, Cunnington thanked those who had supported him during his health crisis.
"For some reason, I'm getting a bit emotional, even though I didn't even win it ... I'm not good with this stuff," he said.
"Just to have the support from the club, the players and my beautiful family -- I couldn't have done it without them.
"You think you're a bit more alone, but the support everyone at the top of the club to the fans stuck at home, it's been huge.
"It actually helps me smile and makes me want to keep continue playing for this great club. It means more than I ever thought."
Cunnington's news comes the day after the Kangaroos announced they were debt-free for the first time since 1987, with former coach Dani Laidley making a rare public appearance to help celebrate the milestone.
Australian Associated Press
Sign up for our newsletter to stay up to date.