Aslan's annual Christmas concert at Vicar Street is a much-loved tradition, but singer Christy Dignam said he won't be "jumping around the stage the way I used to",
The band will play the Dublin venue on Saturday night and said they'll be changing things up with an acoustic set.
"Vicar Street is my favourite venue, anywhere in the world," Dignam said.
"No matter where you are in the audience, you're near the band - it gives a real intimacy to a gig."
Dignam suffers from a rare cancer called amyloidosis, so they'll be performing a stripped-back unplugged set.
"The same passion will be there. We're doing the show this way because I can't be jumping around the stage the way I used to," he said.
"Gigs are more physically challenging now. It has to be more subdued."
The 55-year-old said paring things back also gave the performance a new lease of life.
"Doing something different helps to keep the material fresh for us," he said.
"Having said that, I don't find it hard to keep up my enthusiasm.
"I still love playing songs we've played for 20 years or more, like Crazy World," he added.
Aslan have been together for more than three decades and Dignam said all he ever wanted to do was sing.
"When I left school, I concentrated on finding good musicians to play with, the best drummer, best guitarist, that's how Aslan was formed," he told the RTE Guide.
"My absolute horror was to go back working as a telephone technician.
"I remember my dad giving out to me for giving up a pensionable job to be in a band," he added.