Yoko Shibui, who finished third at last October's Chicago Marathon, has injured herself while training in Kunming in southwestern China and returned to Japan a week earlier than expected for treatment, coach Hideo Suzuki said Friday.

It is unclear whether Shibui will run in Nagoya in March in her bid to earn a spot at the World Championships in Paris in August, as the nature and extent of her injury are unknown.

"At this stage, I cannot say anything about it," Suzuki said after Shibui returned from China on Thursday.

Shibui is aiming to secure a medal as a top Japanese finisher at the World Championships to book a place for the 2004 Olympics in Athens.