Chicago Marathon champion Rita Jeptoo failed a doping test in September, the Kenyan runner's agent said Friday.
Rita Jeptoo of Kenya won her second consecutive Bank of America Chicago Marathon.
Defending champion Rita Jeptoo returns to try and defend her Chicago Marathon crown this year.
Defending champion Rita Jeptoo, Kenenisa Bekele and Eliud Kipchoge will be looking for personal best times on traditionally fast course.
Jeptoo, last year's Bank of America Chicago Marathon runner-up, got her redemption and finished first this year.
Kenyan Rita Jeptoo and Ethiopian Atseda Baysa will duel again this after a photo finish in 2012.
Jeptoo came in second, just behind Atsede Baysa, at last year's Chicago Marathon.
Four of the world’s fastest marathon runners are scheduled to compete in the Bank of America Chicago Marathon next month.