Four-time Olympic gold medallist Sir Chris Hoy has pulled out of track cycling's European Championships.
The 35-year-old Scot withdrew with a chest infection as Saturday's individual sprint began and is very unlikely to compete in Sunday's keirin.
"Chris got up not feeling well. He was dizzy in the warm-up and after a doctor's exam we decided to withdraw him," said GB coach Shane Sutton.
British Cycling head coach
“He's had this lingering for about a week but he went quite deep yesterday, in the team sprint, and that one effort probably pushed him over the edge”
"He'll be disappointed - he was looking forward to the run-out here."
Hoy finished a lowly fifth in Friday's team sprint alongside team-mates Jason Kenny and Matt Crampton after Kenny's wheel slipped at the start of their qualifying run.
At the time he gave no hint of his condition - "on the plus side my lap was quick, so all I can do is focus on tomorrow," he wrote on Facebook - but Sutton confirmed Hoy has had the infection for some time.
"The doctor says he's wheezing quite a lot and has blocked sinuses," said Sutton.
"He's had this lingering for about a week but he went quite deep yesterday, in the team sprint, and that one effort probably pushed him over the edge.
CHRIS HOY'S OLYMPIC YEAR
- Won trio of
at start of October to begin final season before London 2012 in style
- Struggled to
fifth place in Euro team sprint
on Friday after team-mate Jason Kenny's wheel slipped at start
- Withdrew from individual sprint
after initial qualifying stage on Saturday, citing chest infection
- Is expected to be fit to compete at
World Cup in Kazakhstan
- Major targets after that will be
Olympic test event
, which doubles as a World Cup, in London in February, and
in Melbourne a month later
"It's best for him to stop now, go home, recuperate and get ready for [the next World Cup race in] Kazakhstan."
Hoy will miss out on Olympic qualification points that had been on offer at the Euros, in the Dutch town of Apeldoorn, but Britain is so well-placed in the Olympic rankings that his withdrawal here will have no impact on GB's Olympic fortunes.
Even suffering illness, Hoy had qualified fourth-fastest in the individual sprint in Saturday's opening session before deciding to withdraw.
Kenny, sixth-fastest in qualifying, will fly the flag for Great Britain in the men's sprint competition having reached the semi-finals.
Team-mates Victoria Pendleton and Jess Varnish were both eliminated from the women's individual sprint, Varnish exiting in the last 16 before Ukraine's Lyubov Shulika defeated Pendleton in a best-of-three quarter-final.