Danny Bonaduce will undergo brain surgery on Monday.

Two days ahead of the procedure, the “Partridge Family” alum told TMZ that he has been struggling to speak and unable to walk or balance while battling a mystery illness.

After meeting with “100 doctors,” the child actor turned radio DJ was finally given the news in March that he suffers from hydrocephalus.

According to the NIH (National Institute of Neurological Disorders and Stroke), the disorder is “caused by an abnormal buildup of cerebrospinal fluid in the ventricles (cavities) deep within the brain … putting harmful pressure on the brain’s tissues.”

While Bonaduce, who is sober but previously struggled with substance abuse, isn’t sure how he contracted the disorder, he shared some theories with the outlet on Friday.

“I’ve done so many stupid things,” the 63-year-old recalled. “On a reality TV show, I took a guitar to the head and that hurt. That’s possibly the cause of all this.

“I got punched in the face by Jose Canseco, a 265-pound professional athlete,” Bonaduce continued. “And by the way, I didn’t hit the floor, [I] made it on my feet the whole time.”

The “The Danny Bonaduce & Sarah Morning Show” co-host explained that surgeons will put “a shunt in [his] head,” as well as “a drain for it on the back of [his] head” during the procedure.

Bonaduce clarified, “If the diagnosis is correct, I’ll be 50 percent better right away.”

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He went on to acknowledge that while he is “never going to run track” and “never going to box again,” he is hopeful for the future.

“If I can get from here to the kitchen on my own, bravo!” Bonaduce gushed.

His health update comes one year after undergoing a battery of tests when his wife, Amy Railsback, noticed Bonaduce slurring his words and unable to balance.

Following five days in hospital, the former professional wrestler told “Good Morning America” viewers in June 2022 that doctors had ruled out a stroke but couldn’t come up with a diagnosis.