Elliot Wills has had to withdraw from Great Britain's sailing squad for the Rio Olympics later this year due to ongoing treatment for bowel cancer.
The 32-year-old was one of the first British athletes selected for the Games in September along with 470 partner Luke Patience.
However, Willis was diagnosed with cancer in December and his current treatment means that he will miss much of the build-up and not be able to travel to Brazil.
Patience has therefore been de-selected and must attempt to re-qualify with a new partner.
"Clearly Elliot's situation is one neither of us foresaw when we embarked on our campaign together and I'm sad that we won't be able to compete together in Rio this summer," said Patience.
"The thoughts of all the team continue to be with Elliot in his ongoing recovery. For me, it's absolutely the right thing to do to see through the work Elliot and I started out together.
"I'm aiming to re-qualify for Rio with Chris (Grube) and do the best job we can to bring home a medal."