Roger Federer has pulled out of this week's Japan Open in Tokyo citing fatigue.
The world number one has been on the go for several weeks, with appearances in the Montreal and Cincinnati Masters before the US Open and Davis Cup.
Organizers said doctors had advised the Swiss star to rest for at least 10 days before returning to competitive action.
Spaniard David Ferrer will now become top seed ahead of Thomas Berdych of the Czech Republic and Frenchman Richard Gasquet.
In the women's event Venus Williams, fresh from her victory in Seoul on Sunday, heads the line-up with India's Sania Mirza and Maria Kirilenko seeded second and third.

London calling Murray
ATP World Tour Finals Preview
Djokovic v Monfils
Monfils v Stepanek
Nadal v Tsonga
Djokovic v Soderling
Djokovic v Nadal
Clement v Djokovic
We take a closer look at the ATP World Tour Finals and give our verdict on the likely finalists in London.
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