The rapper, who joined forces with Ozzy last year on ‘Take What You Want’, also admitted he had “no idea” that the 71-year-old was battling the neurological condition while they worked together.
“Working with him and hanging out with him and being around him, you can’t tell,” Posty told Rolling Stone. “You can tell he has a little difficulty getting around, but he’s so strong.”
He added: “I know he’s been working on a new project with a bunch of my friends, [and] I’m really excited for him because he’s so passionate about it and it sounds incredible; he sounds incredible.”
Osbourne was first diagnosed with a form of the condition called PRKN 2 after he suffered a fall in February last year.
In April last year, he fell in the middle of the night while going to the toilet, which impacted metal rods that were implanted after a motorbike accident in 2003.
“I feel better now I’ve owned up to them [my fans] about having Parkinson’s,” Ozzy said recently of his diagnosis.
“To hide something is hard – you never feel proper. You feel guilty. I’m no good with secrets. I cannot walk around with it anymore. It’s like I’m running out of excuses.”
Osbourne recently released ‘Ordinary Man’ – a collaboration with Elton John. His album of the same name will arrive on February 21.