They said they had hoped The Who Hits 50! tour would go ahead when Daltrey's condition improved. The dates are now being rescheduled for Spring 2016.
They said Daltrey had been especially disappointed to miss the Teen Cancer America benefit in Los Angeles, a charity he and the band have supported in every way they can.
Pete Townshend also apologised to fans who have supported them in the last 50 years. He said they will come back stronger than ever to give the best show yet.
Just imagine doing the same thing for 50 years. Okay, they haven't been sweating over a sewing machine in the heat of Mumbai, or cooking over a wok in the streets of Chinatown. Their work is held by many as the ideal life-style, adored by fans and living in luxury. But still, they've stuck it out, whereas many bands have folded.
Don't know who The Who are?
The Who are an English rock band that formed in 1964. Their classic line-up consisted of lead singer Roger Daltrey, guitarist Pete Townshend, bassist John Entwistle, and drummer Keith Moon.
Remember the songs: My Generation (1965) Shaking All Over (1970) Won't Get Fooled Again (1971) & Who Are You [Themes of CSI television series] and Summertime Blues to name a few.
It's funny how certain songs from the past remain fixed in your memory.
What do you recall about The Who's music?