The 71-year-old comedian, best known as voicing Hey Hey's puppet Dicky Knee, will undergo a 10 hour operation where his jaw will be removed and replaced with a part of his thigh bone, as revealed on A Current Affair.
The marathon surgery comes after Blackman was diagnosed with an aggressive form of skin cancer, basal-cell carcinoma, with doctors fearing it would spread to his brain if not removed quickly.
“(My surgeon) said, ‘well, just get prepared to not be able to do all the things you’ve been able to do for the past 50 years’, which is a bit of a kick in the guts,” Blackman said.
“To perform, you have to look good, you have to sound good, you have to sound confident and be confident. I just won’t be able to do that anymore.
“Life without doing that is just so alien to me, Marty, I mean, I don’t know what I’m going to do.”
Wishing John good luck with his surgery.