World number one tennis player Justine Henin-Hardenne will not take part in next month's German Open because of a viral infection, organisers said on Thursday.

The Belgian, who withdrew from the Family Circle Cup in Charleston earlier this month, has been ordered to rest by doctors and has decided not to enter the May 3-9 tournament in Berlin.

The 21-year-old is due to defend her crown at the French Open starting on May 24 in Paris.

Former world number one Arantxa Sanchez-Vicario of Spain, who played the German Open 12 times and won it in 1995, will make her comeback this year in the doubles competition.

Organisers said the 32-year-old, who plans to play at the Olympics in Athens in August, had been granted a wild card.