Welsh cyclist Geraint Thomas will be unable to defend his Commonwealth Games road race title in 2018 because of a clash with his Team Sky schedule.
Thomas, 30, won gold at the 2014 Games in Glasgow, staged in July and August.
But the 2018 Games on the Gold Coast in Australia will take place in April, likely to coincide with several Team Sky races such as Paris-Roubaix.
Fellow Welsh riders Luke Rowe and Owain Doull will also be missing because of their Team Sky commitments.
"Unfortunately I think the three of us will be out of it," Thomas told BBC Wales Sport.
"Where they fall in April is the wrong time for us. Luke and Owain will still have the cobblestone classics in Belgium, which will be their main target.
"At the end of the day, Team Sky pay us to race bikes for them and we've got to do what they say. Especially as it's in Australia, it's not like you can fly in and out over a weekend."
The absence of Thomas, Rowe and Doull in Australia will be a setback for Wales, who won five cycling medals at the 2014 Commonwealth Games.
As well as Thomas' road race gold and time trial bronze, Elinor Barker won silver in the women's points race and bronze in the scratch race, while para-cyclist Matt Ellis claimed bronze in the men's tandem 1km time trial B with pilot Ieuan Williams.
Welsh Cycling published its athlete nomination policy for the 2018 Commonwealth Games on Monday.
Performance director Matt Cosgrove said the policy would "give Team Wales the greatest chance of medal success on the Gold Coast".
However, Wales' medal chances will be seriously hindered by the absence of Thomas, Rowe and Doull.
The opening ceremony of the 2018 Games will take place on 4 April, 2018, and the closing ceremony will be on 15 April.
Those dates would clash with a number of important Team Sky races, including the Tour of Flanders and Paris-Roubaix, while later in April there would be other UCI World Tour events such as the Tour de Romandie.
'Commonwealth gold was unbelievable'
Thomas was able to ride at the 2014 Commonwealth Games because it took place after the Tour de France - and he says it remains a career highlight.
"In cycling you hardly get a chance to race for Wales so every chance you do get is amazing and you want to make the most of it," added the double Olympic gold medallist.
"To come away with two medals and win the road race was unbelievable, and something I'll always consider one of my biggest victories."
Thomas and team-mate Rowe are expected to play prominent roles for Team Sky at future Tours, while Doull could feature having joined from Team Wiggins.
Doull, 23, emulated Thomas in winning team pursuit gold at the Rio Olympics but announced at the 2016 BBC Cymru Wales Sports Personality of the Year ceremony that he would not compete at the 2018 Commonwealth Games.
Track cyclists such as Barker are expected to be included in Wales' cycling team for the Gold Coast event when it is named in 2017.