The rocker and "Celebrity Apprentice" star, who was rushed to intensive care late Thursday after suffering a brain hemorrhage, has received a number of messages from other stars on Twitter hoping for his speedy recovery.
Some of Michaels' "Celebrity Apprentice" teammates took to their Twitter accounts to express concern for their co-star.
Sharon Osbourne wrote "I'm thinking of you and wishing you a speedy recovery" to Michaels on her Twitter page.
Holly Robinson Peete acknowledged that Sunday night's episode was a big win for her charity, but added that she will feel "MUCH better when Bret does."
"I will continue to send #bretmichaels all my positive thoughts," Olympian Summer Sanders wrote. "We care about you Bret!"
"He's an amazing guy and very strong and positive," model Selita Ebanks wrote on her Twitter account. "Let's keep the positive energy going!"
Comedian Carol Leifer, who was the first contestant fired from this season's "Celebrity Apprentice," wrote, "We love you, Bret Michaels! Hoping & praying for you, buddy!!"
Maria Kanellis kept her reaction straightforward when news broke that Michaels was rushed to the hospital, posting, "Lets all keep our prayers with Bret."
The reality show's head honcho, Donald Trump, also took to his Twitter account to express concern for Michaels.
"Our thoughts and prayers remain with Bret Michaels and his family for his speedy recovery," he wrote.
Ashton Kutcher also encouraged fans to send good thoughts to Michaels.
"Everybody pray for Brett!" he said.
Meanwhile, doctors plan further testing to help pinpoint the source of the brain hemorrhage that is keeping Michaels in intensive care.
His New York-based publicist, Joann Mignano, confirmed on Friday a report on People magazine's website that said the former Poison frontman was rushed to intensive care late Thursday after a severe headache. Doctors discovered bleeding at the base of his brain stem, the report said.
Michaels had an emergency appendectomy April 12 after complaining of stomach pains before he was scheduled to perform at Sea World in San Antonio. Michaels later wrote on his website that although the surgery "has taken its toll," doctors expected him to make a full recovery.
Before joining the third season of "The Celebrity Apprentice," Michaels starred as the lothario on VH1's lusty reality dating series "Rock of Love" from 2007 to 2009.