Bad luck continues to dog Richie Porte, with the Australian cycling star falling ill two days before the start of the Vuelta a Espana.
News of the Tasmanian's gastro woes came on the same day that his long-rumoured moved to Trek-Segafredo was confirmed.
The 33-year-old will leave BMC and become Trek-Segafredo's Grand Tour leader from the start of next season on a two-year deal.
His main objective next year will again be the Tour de France.
Porte will still lead the BMC lineup in the Vuelta, or Tour of Spain, which is the last three-week Grand Tour of the season.
BMC said in a statement that Porte will not go to Thursday's team presentation or pre-race media conference because of his gastroenteritis.
The plan is for Porte to have a light training ride on Friday ahead of Saturday's start.
"Although this is not ideal ... we are confident that adequate rest will help Richie get back to his pre-race form," BMC doctor Daniel Zaccarria said.
This is Porte's first race since he crashed out of last month's Tour de France at the start of stage nine with a broken collarbone.
He also suffered serious injuries when he crashed out during stage nine of last year's Tour.
The previous year, Porte suffered a shoulder injury when he crashed near the end of the Rio Olympics road race.
The month before, he had his best Tour de France result of fifth - but it probably would have been second had he not punctured in the first week.
Porte is racing the Vuelta because of last month's crash, which forced a change of plans for the back end of the season.
His aim is to build form through the Vuelta and then peak for the world championships road race late next month, where the hilly course will suit his climbing strengths.
Porte is among 11 Australians on the Vuelta start list, including BMC teammate and time trial specialist Rohan Dennis.
The Australian team Mitchelton-Scott will be led by the British Yates brothers, Adam and Simon.
AUSTRALIAN STARTERS AT THE VUELTA
BMC - Richie Porte, Rohan Dennis
Bora-Hansgrohe - Jay McCarthy
Mitchelton Scott - Alex Edmondson, Jack Haig, Damien Howson
Team EF Education First-Drapac - Simon Clarke, Mitch Docker
Sunweb - Jai Hindley, Michael Storer
Caja Rural-Seguros RGA - Nick Schultz.
