Staple, who is currently on tour, failed to join the rest of the band for a special performance at BBC 6 Music last week.
The singer has posted on his Facebook page (here):
"To all the fans who have sent messages and posted stuff on facebook and on the Specials forum pages, I'm sorry to hear that some of you are upset that you bought tickets, before knowing I had decided to not perform with the Specials for BBC and the forthcoming tour.
I made my mind up some weeks ago to take a back seat and was under the impression that tickets wouldn't go on sale until after the BBC performance, when my decision would be made public. However, the ticket link went out earlier and this was out of my control.
I can't jump around like I used to but will be performing now and throughout 2013, with my band as before and hope to see many of you along the way. Please join my facebook page for all ticket updates.
I wish the rest of The Specials all the best in 2013."