Fred Kerley, the U.S. champion and world bronze medalist in the 400m, will instead concentrate on the 100m and 200m at the Olympic Trials that start Friday, according to his social media.
Kerley is listed as “scratched” from the 400m for the Trials, indicating he does not plan to race the event.
Kerley, 26, turned heads in April by clocking personal bests at 100m (9.91 seconds) and 200m (20.24).
On May 19, he ran the 100m and 200m at a meet in Ostrava, Czech Republic, after which he said his plan was to race the 400m at Trials.