Although the two athletes have not been picked for the American team after missing the recent US trials, the sport's governing body, the International Amateur Athletic Federation, is set to give them the go-ahead to run.
Although the IAAF general secretary, Istvan Gyulai, said yesterday that no final decision had been made about wild cards for the championships, an IAAF source was quoted as saying: "I think you will find that there is a majority of people in the IAAF who are in favour of this and it will be in place by Athens.
"Not all athletes and officials like the idea, but it is seen as a way of making the World Championships different from the Olympic Games. It helps top athletes who are injured and missed national trials to make the event. It basically improves the championships as a show."
Gyulai, however, refused to confirm that a majority supported the idea. "People are considering whether to allow it in principle, like they do in football and skiing, but the council has not made a decision yet," he said. "There are views that it could be in the best interests of sport to have the best possible show. But I don't know what the decision will be."
The US has strict rules on qualification for World Championships and Olympics. Only the top three in the national trials qualify for the team.
The appearance of Johnson, who has been struggling with his form in recent weeks after picking up a thigh injury, would provide a major boost to the event after he dominated last year's Atlanta Olympics.
US track and field officials have refused to change their qualification rules, but have said they would welcome the IAAF inviting 1995 world champions to defend their titles.
The IAAF council does not plan to hold a special meeting to make the decision, but council members can make their views known by post. Many nations reserve places in their teams for elite athletes to avoid problems with competitors who are out of form at the national trials, but the Americans believe they must have one clear way of picking the team.
The American world shot champion, John Godina, who finished out of the top three at the trials, the sprinter Gwen Torrence and the decathlete Dan O'Brien would also benefit from the ruling - and it could also help leading Kenyans to compete, even if they failed to perform well at the national trials. The double world 5,000 metres champion, Ismael Kirui, was one who struggled at last week's trials.