US sprinters look to lay down a marker in Tokyo

Long operating in the shadow of publicity magnet Richardson, Jefferson-Wooden calmly built up a healthy collection of sprint relay golds, before taking bronze in the Olympic 100m last year.

This year, she has become the main event — on the track at least — claiming impressive Diamond League victories over 100m and also clocking a personal best 21.84 in the 200m.

"The plan is definitely to go out there and take gold," she said of the Tokyo challenge. "I feel like I put myself in a really good spot to be a contender for that and now it's time to have trust."

Both women are coached by former Olympic sprinter Dennis Mitchell, who was banned for two years in 1998, during his competitive prime, for doping offenses.

Shelly-Ann Fraser-Pryce is unlikely to claim a sixth world 100m title at the age of 38, but the smiling Jamaican will be assured of the warmest of send-offs as she says she is retiring after the event.

In a blow for the family, but a bonus for TV commentators, Tina Clayton looks like Jamaica's best prospect after twin sister Tia, owner of the fourth-fastest time in the world this year at 10.82, misses out after pulling up injured in the final of the country's trials.

Jamaica's Shericka Jackson will bid for a third successive 200m gold, but has struggled to reach peak form this season, as her best of 22.17 makes her only the eighth-fastest in a field that does not include US Olympic champion Gabby Thomas, who is absent with an Achilles injury.

Reuters