World Championship squad

Allyson Felix: US Olympic great named in World Championships squad

Felix, the most decorated female track and field Olympian of all time, will retire at the end of the season.

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.