Sir Chris Hoy will not defend his individual sprint title at the London Olympics, British Cycling have confirmed.
The Scot, 36, will compete in the men's Keirin while team-mate Jason Kenny will contest the sprint.
British cycling performance director Dave Brailsford had elected the leave the decision on who will contest the sprint as late as possible, but Kenny has been given the nod after he finished in second place ahead of Hoy at the World Championships in Melbourne earlier this year.
Hoy and Kenny will both compete in the men's team sprint alongside Philip Hindes and reserve Ross Edgar.
Hoy said: "Whilst I'm obviously disappointed not to be defending all three of my 2008 Olympic titles in London, Jason thoroughly deserves this opportunity and has a great chance of success in the sprint.
"I am now focused entirely on the keirin and team sprint and my goals for those two events haven't changed."
Brailsford said: "We have now finalised our selection for the track events and in particular we have made the decision over who will ride the sprint.
"Both Chris and Jason are on great form and that made it a difficult choice, but we have decided to select Jason to contest the sprint and Chris will concentrate on the keirin. We believe this gives us the strongest team possible going into the Games."
Bolton rider Kenny, 24, finished second behind Hoy in the sprint in Beijing. But the pair have been evenly-matched when they have gone head-to-head recently.