Leslie West, the singer-guitarist for classic-rock band Mountain, had to have his lower right leg amputated on Monday. The procedure was required to prevent a foot infection from spreading further into his body.

West's leg started to swell up on Friday during a flight from New Jersey to Biloxi, Miss. He was slated to perform a show with his band that night.

"The doctors tried for two days to save it to no avail. The decision to amputate was one that was necessary to save his life as the infection was spreading throughout his body," his wife, Jenni West, wrote in an email statement. "The nursing staff and doctors have taken excellent care of him and should be called angels for their efforts and tenderness they showed us in this time of crisis."

Mountain are best known for their hit 'Mississippi Queen,' and are considered a pioneering hard-rock act. West, a large man who has battled weight issues his entire life, suffers from type 2 diabetes. He had recently recorded a new album, 'The Unusual Suspects' that includes guest spots from Slash, Zakk Wylde and ZZ Top's Billy Gibbons. A release date has not been announced as of yet, but the disc may surface in the fall or early 2012.

West is expected to recover from the procedure, but will need months of rehabilitation.

Watch Mountain Perform 'Mississippi Queen' in 1970