Richie Porte, Chris Froome's faithful lieutenant, will miss May's Giro d'Italia to focus on the Tour de France, Team Sky have announced.
The Australian was tipped to lead Team Sky at the Giro, which begins in Belfast on May 9, to take aim at the pink jersey, the maglia rosa.
Instead, Team Sky's Giro leader is yet to be confirmed, with Porte's full attentions now on supporting Froome's bid to retain the yellow jersey, which will begin in Leeds on July 5.
Team Sky head of performance support Tim Kerrison said on teamsky.com: "Richie was always going to ride the Tour de France this year, but this now means that he can fully focus on being in the best possible shape without having the added challenge of having to ride the Giro as well.
"He played an invaluable role in our Tour wins in 2012 and 2013 and we want him to do the same again this year.
"We're always reviewing our line-ups and looking how we can best support our riders and give ourselves the best possible chance for success."
Sir Bradley Wiggins, the 2012 Tour winner, is also hoping to be in the Team Sky squad for the Tour.
Wiggins, who missed the 2013 race through injury, will ride the Paris-Roubaix one-day race on Sunday.