Alessandro Ballan won the Driedaagse De Panne in 2006, but for this year's race he will not be riding his bike. Instead he is ill. He has missed quite a big part of the spring season due to a cytomegalovirus - a herpes-type virus that causes tiredness and fever - and he will not be able to ride the Spring Classics either, but the world champion will help his Lampre-NGC teammates anyway as they prepare for the Paris-Roubaix, where he finished third in 2008, but of course he will not race in it.
"I am doing better, and next week I will have some more exams to check the status of the virus," he said in video press release at Lampre's homepage. "I would like to head north on the eve of the Paris-Roubaix to reconnoitre some of the sectors with my teammates."

The rider had to withdraw from the Tirreno-Adriatico stage race in mid-March and he has not been able to race since then. He had a big wish of winning the Ronde van Vlaanderen, a race that he won in 2007, but he will not be there this Sunday (of course). Perhaps it's the curse of the World champion jersey, but I really had hoped to see him in the spring classics.
"It will be hard to have another occasion to race the Northern Classics with the World Champion jersey. ... My objective is to return for the Giro d'Italia." Ballan said.
And yes, it may be difficult. Ballan may not be double world champion, he is not a supersprinter who can win races all the time, but instead he needs to be clever to win. But it is true, he is quite clever so it's possible for him to win the world championship another time, but it might be difficult.