Gilbert, known for his work on iconic TV show Hey Hey It's Saturday, underwent surgery in The Alfred hospital in Melbourne.

An Alfred spokesman said Gilbert remained in a serious condition.

Profile Talent Management issued a statement on Friday: "Russell Gilbert underwent surgery today for a brain aneurysm," it said.

"A long and slow recovery is expected. The family has asked that their privacy be respected during this difficult time."

A grief-stricken Gilbert did not attend the funeral of his long-time girlfriend and fiancee, Rochelle Nolan earlier in the week.

Ms Nolan, who died on September 10, was farewelled at Brighton's Baptist Church on Tuesday.

Gilbert wrote "A Short Note" in the Order of Services booklet.

"Thank you everyone for your words of comfort and support," it read.

"As you could all imagine, today is the hardest day of my life! It is with the greatest sadness that I do not have the strength to be here with you all today. I'm just not ready (to) say goodbye."

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