Olympic great Allyson Felix could make her 10th and final World Athletics Championships appearance later this month after being named in the United States 4x400m mixed relay pool.

The 36-year-old has won 19 world medals in her career, including 14 gold.

She failed to qualify for the individual 400m event after finishing sixth in the US trials.

There is no guarantee Felix will feature as she is one of four female athletes named in the mixed relay pool – with two men and two women to run per team in each race.

She made her first World Championships appearance at the Paris event in 2003 and competed at her fifth and final Olympics in Tokyo last summer.

The World Athletics Championships will take place between 15-24 July in Eugene, Oregon.