Bassist Deacon retired from the legendary rock band in 1997 - six years after his lead singer Mercury died from AIDS-related complications - and he has tried to stay out of the limelight ever since.
Now drummer Taylor is worried about his pal's health, telling The Telegraph on Saturday (18Sep21), "(John)'s quite fragile. He took Freddie's death so hard."
Deacon was not present at Queen's induction into the Rock and Roll Hall of Fame in 2001 and Danny Miranda from Blue Oyster Cult took over bassist duties when the band teamed up with Bad Company frontman Paul Rodgers in 2004.
And Roger admits all the original bandmembers struggled after Freddie's passing.
"It was a dark period, a massive loss," he says. "It wasn't just the band, it was more personal than that. I think it took five years for it to really sink in."
The "We Will Rock You" hitmakers threw themselves into a tribute concert at Wembley Stadium in 1992 and went on to complete a posthumous album, "Made in Heaven", in 1995, but they were convinced Queen would not survive their frontman's loss.
"It was a way of diverting some of the grief," explains Taylor. "We thought that was it. It was wonderful. But it was over."
But Taylor and guitarist Brian May returned to touring in 2011, with "American Idol" star Adam Lambert on vocals, and Queen have once again become one of the highest-grossing live acts in the world, while their 1981 Greatest Hits album remains the biggest-selling release in British history.
"Ultimately, I think it's the strength of the material," added the sticksman. "There's no master plan, just constant attention to doing stuff and keeping the embers glowing."