Sammy Hagar has confirmed what we've been reporting, that it's Jason Bonham's mother Pat who is seriously ill back in England.
Kenny Aronoff sat in for the last four shows, and he's on standby for the three dates in Japan later this month.
Hagar broke the news about Pat during an interview before the U.S. finale of The Best of All Worlds tour this past Saturday in Maryland Heights, Missouri.
Pat Bonham is 76.
In addition to Jason, Pat and her late husband John have daughter Zoe.