American Michael Norman will not defend 400m World Championship title in Budapest

Norman produced a memorable performance to triumph in Eugene last year after a succession of career disappointments, including a shock fifth-place finish in the Tokyo Olympic final.

"Unfortunately I will not be defending my title at the 2023 World champs," Norman said in an Instagram post.

"After an extremely frustrating season, I’ve decided to step away from track for the remainder of the 2023 season in order to refocus for the 2024 Paris Olympics."

Norman had scarcely competed this year and withdrew from the LA Grand Prix in May after finishing eighth in the 200m at the Doha Diamond League meet.

The announcement further dented American hopes to top the medal table again following a dominant 2022, after Sydney McLaughlin-Levrone pulled out citing a minor knee issue.

McLaughlin-Levrone, who broke her own world record to win the 400m hurdles last year, had been expected to compete in the flat event.