USA's Allyson Felix and David Oliver spoke about Justin Gatlin at a news conference with Jenny Simpson ahead of the World Championships in Beijing, China.

Script: SOUNDBITE (English) Allyson Felix, USA

Q: Will you be cheering on Justin Gatlin?

'I am going to be cheering on all my teammates'

SOUNDBITE (English) David Oliver, USA

"He is just doing his job, running and running fast and i am happy for him, that's a you problem, you keep bringing it up over and over focusing on that when there is tonnes of other athletes that are representing the USA that warrant the same type of attention, but i am rooting for him and i hope he does well."

SOUNDBITE (English) Jenny Simpson, USA

"I remember arriving at Daegu and everybody being drug tested and i was really excited to see that development in our sport and i think deep in my heart that was why i was successful there in 2011, moving on to 2012 what we are seeing now is a demonstration of a really unfortunate thing that there are people in the final kept clean athletes like myself from reaching the finals so i think those sort of situations are really unfortunate to see in our sport."

SOUNDBITE (English) Allyson Felix, USA

"It was very difficult, everybody knows that i just love the 200, and going to a championships and not being in it,its difficult, i cant even imagine having to watch and seeing results and wishing i was in it, but i did feel good that so many times i had a chance to run that at a championship so i do feel like its time to step up."