Iron Maiden drummer Nicko McBrain was left "paralyzed" after suffering a stroke earlier this year.
The rocker, 71, wrote about his "very serious health problem" on Instagram on Aug. 3.
"In January I had a stroke, thank the Lord it was a minor one referred to as a TIA. It left me paralyzed on my right side from my shoulder on down," the rocker said.
Nicko feared for his career, but said he's about 70% recovered now.
"After 10 weeks of intense therapy it was almost time to start rehearsals for our tour," he wrote. "I feel it's important to let you know about this now instead of earlier as I was mainly concerned with doing my job and concentrating on getting back to 100% fitness. I'm not there yet but by the grace of God I'm getting better and stronger as the weeks go by."
Iron Maiden's manager, Rod Smallwood, said he Nicko's bandmates have been marveling at his recovery.
"What Nicko has been able to achieve since his stroke shows incredible belief and willpower and we are all very proud of him," Rod said. "With this new and musically very complex set to learn ahead of him, he just got his head down and concentrated on recovery. We honestly did not know if he would be able to play a whole show until band rehearsals started in May and there was just so much support for him from the band and then genuine relief for all when we saw he was going to be able to do it!"
"Nicko being Nicko, he did not want to make a fuss and cause any distraction to the tour at the time but, now that he is sure he will soon get there, he thought you fans should know straight from him rather than by any rumors," Rod concluded.