LONDON • The insurance coverage for a Rolling Stones tour of North America would have mandated that every band member is in good health.
Fans speculate that is why the tour has been postponed, with frontman Mick Jagger reportedly set to undergo heart surgery on Friday.
American website Drudge Report said Jagger, 75, is going to replace a heart valve.
New York Post's Page Six website said the surgery would involve placing a stent in the singer's heart.
The band last Saturday announced that they are postponing all dates on their tour of the United States and Canada to give Jagger time to receive medical treatment.
They did not specify what treatment he needs, but noted that he is expected to make a full recovery.
The North American tour had been scheduled to run from April 20 to June 29.
Jagger was photographed on Sunday in Miami Beach city, Florida, on the beach with his girlfriend, ballet dancer Melanie Hamrick, 32, their young son Deveraux, two, and his daughter Georgia May, 27, one of his seven adult children with other women.
The British singer has not explained his medical issue, but told fans in a tweet last Saturday that he would be "working very hard to be back on stage as soon as I can".
After a storied wild lifestyle in his younger days, Jagger now follows a healthy diet, runs and works out frequently.