The Chinese hurdler has not been on the track for almost three years, as he has struggled with a right Achilles tendon injury he picked up in 2012.
When asked whether he would be able to compete in the World Championships, Xiang said: "I think the possibility is pretty slim. I might be able to take part in the event in another role.
"A lot of young athletes have emerged as high-level contenders in the world. Some have already been able to reach the top eight or win medals in their respective events. I hope the public could pay more attention to them and the coming championships."
The hurdler won gold at the Athens Olympics in 2004, and again in the 110m hurdles at the 2007 Worlds in Osaka, Japan.