Mustaine, a member of Metallica from 1981 to 1983, said the band's inaugural 2019 Megacruise will still happen, but most shows this year have to be canceled.
The Megacruise is five days and departs Oct. 13 from Los Angeles with stops in San Diego, California, and Ensenada, Mexico.
It is not clear how they will be involved, but Mustaine said Megadeth will be back on the road as soon as possible.
"I'm so thankful for my whole team – family, doctors, band members, trainers, and more," Mustaine said. "I'll keep everyone posted."
The singer and guitarist said he and the rest of the band -- guitarist Kiko Loureiro, bassist David Ellefson and drummer Dirk Verbeuren -- are in the studio working on new music.