Britain's Mark Cavendish has pulled out of Wednesday's Grand Prix de l'Escaut because of flu, his Omega Pharma team confirmed.
"This flu has really weakened him and for a rider like him it makes no sense to start at only 50percent of his form. So we decided to let him rest," said team manager Patrick Lefevere.
"We're also going to rethink our programme. He'll probably be at the Tour of Turkey (April 27-May 4), at the Giro (May 9-June 1) and the Tour of California (May 11-18)," said Lefevere.
Cavendish has close links with the Grand Prix de l'Escaut, which is held on a flat course in the Flanders countryside and is seen as ideal for sprinters. His victory in 2007 was the first big success of his career and he followed up in 2008 and 2011.
The 28-year-old former world champion also missed the Gent-Wevelgem and the Three Days of La Panne races this season.
In the absence of Cavendish and Germany's Andre Greipel (broken collarbone), Germany's Marcel Kittel will be favourite to defend his title.
Also expected to challenge are Belgian duo Tom Boonen and Kenny Dehaes, Italians Alessandro Petacchi and Andrea Guardini, Slovak Peter Sagan, France's Arnaud Demare and Milan-SanRemo winner Alexander Kristoff of Norway.
Swiss Fabian Cancellara, who won his third Tour of Flanders on Sunday, is also set to compete.