The 'Invisible Touch' hitmakers - comprising Phil Collins, Mike Rutherford, and Tony Banks - are set to embark on their first concert series since 2007 and though they can understand why fans would like to see them joined by their former members, they don't think it would work with all five of them.
Asked about the possibility of getting Peter, who left in 1974, and Steve, who quit three years later, involved, Phil said: "I think a reunion with Steve and Pete would be uphill. Playing with Mike and Tony is the easy option."
Mike added: "I know people love the idea that the five of us will get together again, but the songs most people know and love are from the last 40 years. Peter left so long ago. I really don't know what we could do with him now."
Tony told MOJO magazine: "As much as I love those early albums, it would be weird to just do songs from that period."
As with Phil's comeback solo tour two years ago, his 18-year-old son Nicholas will be covering for him on drums because the 'In the Air Tonight' hitmaker is no longer able to play because of a spinal condition.
Phil insisted: "I didn't elbow him into the band. You can't force a drummer onto these guys."
But his bandmates had some initial reservations about enlisting the teenager.
Tony said: "When I first heard Phil was using Nic, I thought it was a stupid thing to do. Nic was only 16.
"But then reports started coming back about how good he was, the real deal.
"I saw Phil's show at the Albert Hall and Nic was just incredible."
Recalling their first rehearsal together, he added: "The first songs we played were 'No Son of Mine' and 'Land of Confusion'.
"Mainly because they're the two easiest. "Nic knew them better than we did. He showed us up - embarrassingly so."
While the trio are looking forward to the tour, they've no plans to make a new album.
Mike said: "It's not on our radar, no. This tour is a big undertaking in itself."