Mark Cavendish has been among those to offer support to Nicky Hayden, the former MotoGP world champion who is in intensive care after being being involved in a collision with a car while cycling in Italy.
Hayden was cycling in Rimini in eastern Italy when he was knocked off his bike on Wednesday afternoon, suffering serious head and chest injuries.
The 2006 world champion was transferred to a hospital in the nearby city of Cesena where doctors said on Thursday morning that his condition "remains extremely serious".
On Wednesday the hospital said that Hayden had suffered multiple fractures and a cerebral edema, but were waiting until his condition had stabilised before carrying out any operations.
Mark Cavendish, a keen MotoGP fan himself, was among those to offer his support to Hayden and his family and friends.
Hayden's current team, Red Bull Honda, said that they were thankful for the messages of support, saying only that the medical teams in Italy were working hard and they would provide updates as soon as they are available.