Brian May has been suffering from daily "brown-outs" since contracting COVID-19.
The Queen legend fell ill with the virus in December 2021 after a birthday lunch with friends, and he has been dealing with a "strange" condition which causes him to suddenly fall asleep.
Appearing on the 'How Do You Cope podcast, he said: "I have a strange persisting condition, I think from the COVID, which are kind of brown-outs...
"Generally I'm OK, I'm not tired all the time, but I'll get to a certain point in the day where something inside my head goes, 'You have to sleep now. You don't care about any of this, go to sleep - who cares?'
"It's an almost irresistible call and I just go out like a light. It's really weird."
The 74-year-old guitarist admitted he was concerned about the way the condition could impact his life on tour.
He added: "It's an almost irresistible call and I just go out like a light. It's really weird.
"I just hope it doesn't happen in the middle of a gig, because it's going to be very embarrassing - 'Just hang on for half an hour while I have a nap, guys - then we'll do We Are The Champions.'
"But I feel good, I don't know if it's changed me."
The 'Don't Stop Me Now' musician shared the news of his positive COVID-19 test just before Christmas last year as he posted a photo of his test result on Instagram.
He wrote at the time: "Yep. The shocking day finally came for me. The dreaded double red line.
"And yes - definitely NO sympathy please - it has been a truly horrible few days, but I’m OK. And I will tell the tale.
"PLEASE take extra care out there, good folks. This thing is incredibly transmissible. You really do NOT want it messing up YOUR Christmas. (sic)"