He’s been fronting his self-titled solo band on the travelling Gigantour festival, headed by Megadeth and also featuring Black Label Society, Device, Hellyeah and Death Division.
The band will miss the event’s upcoming shows in Canada, but Newsted aims to be back next week.
He says: “I’d been felling a bit under the weather while performing the most recent shows, so I went to the doctor on my day off today and I was diagnosed with walking pneumonia.
“So under doctor’s orders I’m taking a week to rebuild. My apologies to our Canadian brothers and sisters – I’m going to work on keeping me alive so together we can keep the metal alive!”
Walking pneumonia is the least serious variant of the lung illness and doesn’t usually require hospitalisation.
Megadeth frontman Dave Mustaine has sent a message of support in which he appears to invite Newsted to join him on stage for a rendition of a Metallica track. He says in a tweet: “Jason, we heard you’re ill. So bummed, and I’m sure the fans are too. Get well soon. Metal Militia when you return?”
Meanwhile, Newsted the band have released a teaser containing clips from all 11 tracks of upcoming debut album Heavy Metal Music, due out on August 5. Hear it below.