It’s not good news for 2018 Tour champion Thomas, as both Brits will look to compete for the yellow jersey
Team Sky team-mates Chris Froome and Geraint Thomas will both target the Tour de France in 2019.
Four-time champion Froome has decided not to defend his Giro d’Italia title this season to instead focus on winning a record-equalling fifth Tour crown.
It reads as bad news for Thomas, who also plans to compete for the yellow jersey in France having won the race for the first time in the summer.
The Welshman was crowned BBC Sports Personality of the Year last month after becoming the third Brit to win the iconic race.
It also meant the Tour de France was won by a Brit for the SIXTH time in seven years, since Sir Bradley Wiggins become the first Britain to win the race in 2012.
But he will have to compete with team-mate Froome this year, with young Colombian Egan Bernal set to lead Team Sky at the Giro d’Italia instead.
Froome said: “I’m getting to the point in my career now where I’m starting to think about what kind of legacy I want to leave behind and if I am able to win the Tour de France for a fifth time and join that very elite group of bike riders – only four other people have ever done that – it would just be incredible.”
Thomas added: “Maybe if I hadn’t have won the Tour in 2018 I might have looked at a Giro/Vuelta programme but, having won the Tour, I’ll have the number one on my back and it would be sad not to go back and not to go back at 100 per cent as well.”
Thomas won the Tour in July despite Froome starting the race as Team Sky’s leader, with the Welshman proving the stronger of the two after Froome’s exploits in winning the Giro a little over a month earlier.
Froome, 33, needs one more Tour title to match the record jointly held by cycling legends Eddy Merckx, Jacques Anquetil, Miguel Indurain and Bernard Hinault.
Colombian Bernal secured a 15th-placed finish in last year’s Tour riding in support of Thomas and Froome, and is viewed as one of the sport’s brightest prospects.
“The Giro is a race that I really, really like,” the 21-year-old said.
“I lived in Italy for three years, so I have a lot of friends there and I really like the Italian fans. I know the roads, I really like the Giro, and I want to do a good race there.”
Team Sky’s riders go into the season facing an uncertain future with the broadcaster due to end its investment in the sport after the coming season.