Sharon Osbourne doesn't just star with Bret Michaels on the current season of NBC's [article id="1637831"]"Celebrity Apprentice,"[/article] she's counted him as a close friend for nearly 30 years.

So when she learned of the [article id="1637778"]Poison frontman's brain hemorrhage[/article] and subsequent [article id="1637746"]stint in an intensive care unit[/article], she was crushed.

Bret Michaels' Career In Photos

"[It's] just hideous," Osbourne told Us Weekly on Tuesday (April 27.) "It's devastating, and it makes you feel all these different things. Your heart goes out to his family, your heart goes out to him. He's the nicest guy in the world. And then you start thinking about your own mortality. You start thinking, 'Oh my God.' It just makes you appreciate how lucky we all are."

Osbourne added that the last time she had seen Michaels, he was "absolutely" in good health.

She wasn't the only [article id="1637857"]friend of Michaels' to comment[/article] on the ailing rocker's health. His "Apprentice" co-star Bill Goldberg told RadarOnline.com that he had recently spoken to Michaels and advised him to "slow down with his lifestyle," and "Apprentice" boss Donald Trump told the "Today" show that Michaels was "a real competitor ... he would work so hard, maybe harder than anybody else. And he's doing well."

And on Tuesday, Pete Evick -- Michaels' friend and guitarist in the Bret Michaels Band -- posted a lengthy message on BretMichaels.com, which thanked fans for the "overwhelming love and well wishes" the rocker has received and paid tribute to a man he called "a loyal friend" and a fiercely hard worker.

"When I was invited into Bret's world, over 5 years ago, I was introduced to a new level of strength and loyalty ... so much that I had to rethink my whole life and how I do things. I didn't understand what it meant to be a loyal friend. The kind that would do anything you ever needed without even asking why, what, who or where," Evick wrote. "Bret is the kind of guy that wakes up every day and treats it like it is his first, and may be his last. He is full of passion, energy and love. But most of all, he is a survivor. Against the odds of a critical music industry, or battling a crippling disease, over and over again Bret has come out on top and ahead of the game. I personally expect nothing less from him in this situation."

Share your own well-wishes for Bret Michaels right here in the comments.