Rio 2016 Stars: Allyson Felix
United States star Allyson Felix is expected to shine at Rio 2016, although she has been denied a golden sprint double.
Sport: Athletics (200m)
Country: United States
Date of birth: November 18, 1985
Career highlights: Four-time Olympic champion and nine-time world champion; World record holder in 4x100m relay.
Olympic record: Athens 2004 – silver (200m), Beijing 2008 – 1 x gold, 1 x silver (4x400m relay, 200m), London 2012 – 3 x gold (200m, 4x100m relay, 4x400m relay)
American sprint queen Allyson Felix will miss out on a slice of Olympic history, but could be set to benefit from having her attention focused ahead of Rio 2016.
Felix was originally pegged as one to watch after confirming her intention to compete in both the 200 metres and 400m in Brazil.
Having eased into the reckoning in the 400m by winning her US trial, the 200m Olympic champion shockingly failed to qualify in the shorter distance, losing out to Tori Bowie, Deajah Stevens and Jenna Prandini by just 0.1 seconds.
Hampered badly by an ankle injury picked up in April, Felix struggled for stamina - as she had when attempting both events at the 2011 World Championships.
"The whole year, that has been what I was working for," said Felix after missing out on her favoured event.
"When I look back and see everything what happened, I still think it's quite amazing I was able to make the team.
"I could only do what I could with the ankle."
Felix's personal best in the 200m is 21.69 seconds, but she was unable to get anywhere near that in Eugene during the trials.
"The speed just wasn't there, period," she said. "When I give all I have and I run 22.5 it's just not there."
As such, Felix is denied the chance to join Team USA's Valerie Brisco-Hooks, American track legend Michael Johnson and France's Marie-Jose Perec in winning both events in a single Games.
The scheduling of the sprint races in Brazil had been specifically altered to help Felix in her quest to add her name to that list.
Originally, the first round of the women's 200m had been due to take place 75 minutes before the final of the 400m, which would have realistically ruled anyone out of doubling up.
However, after USA Track and Field lobbied the IAAF, the women's 200m opener was moved from the evening to the morning of August 15, extending Felix's potential rest time to 13 hours.
Although that is now largely immaterial, Felix will remain busy. Factoring in potential involvement in both 4x100m and 4x400m relay races - she contributed to the United States winning gold in both at London 2012 - the 30-year-old could race seven times across eight days.
Felix should take confidence heading into uncharted Olympic territory, having won 400m gold at last year's World Championships.
Bahamian Shaunae Miller took silver in Beijing and looks set to be a major challenger again, leading the 400m standings in the Diamond League after registering a world-leading 49.55seconds at the London meeting shortly before the Games.