AceShowbiz - A former bandmate of hospitalized rocker Gustavo Cerati has urged fans to "have faith" after the Argentinian star underwent brain surgery following a mini-stroke. The singer was admitted to a hospital in Venezuela after collapsing at the end of his gig in Caracas on Saturday, May 15.

Doctors confirmed Cerati suffered an "ischemic vascular event", a condition known as a mini-stroke which reduces blood flow to the brain, but the 50 year old's health hit further trouble when surgeons were forced to operate to remove a potentially-fatal blood clot on Tuesday, May 18.

He is now recovering in intensive care and his progress over the next few days will prove "critical", according to hospital director Adolfredo Saez. Cerati's former Soda Stereo pal, Charly Alberti, admits the news hit him hard and he's praying the singer makes a full recovery. The drummer says, "We must have faith. My head has been boiling since I found out on Sunday."

And Ricky Martin has also offered his support to the ailing rocker. In a post on his Twitter.com page, he writes, "Strength Cerati, we want you well!"