Athletes must choose their coaches carefully to avoid any risk of guilt by association, global athletics boss Lord Sebastian Coe said on Wednesday, two days after leading American coach Alberto Salazar received a four-year ban.
Salazar was banned by the U.S. Anti-Doping Agency (USADA) on Monday for "orchestrating and facilitating prohibited doping conduct" as head coach of the Nike Oregon Project (NOP), a camp designed primarily to develop U.S. endurance athletes.
Salazar said he would appeal USADA's decision and sportswear giant Nike said it would stand by him.
A number of the athletes competing in Doha train at the NOP, including women's 10,000 metres gold medallist Sifan Hassan of the Netherlands and American Donavan Brazier, who won Tuesday's men's 800 metres final.
"A banned coach has to sever relationships with those athletes, that's what's taking place," said Coe, who was elected for a second term as president of the International Association of Athletics Federations (IAAF) last week.
"Coaches and athletes have to make judgements all the time. If you are coached by somebody, you should be absolutely comfortable that you are working in an environment that's safe and secure and is not going to damage your own reputation.
"An athlete should ask those questions."
Coe said, however, he did not see any risk that NOP athletes would be tainted by the USADA ruling.
"No, no, I'm sorry," he said. "I don't live in that world where you just automatically assume the worst.
"It's what happens. We're dealing with it. It doesn't derail the championships.
"It may for you guys, but in reality it's not a broader issue for most people watching the championships."
Coe did not want to comment on the state of the NOP itself.
"I have no idea [what's going on]," he said. "I haven't even read the adjudication. It's not a programme I'm remotely across or I understand."
Coe also defended the organisation of the World Athletics Championships in Qatar, saying the athletes were not worried about small attendances at the Khalifa stadium.
The Brit said he spent every evening on the track talking to athletes, medical staff and delegates, and that they were happy with the organisation of the competition despite the low attendances.
"They are very pleased to be here," he said. "Yes, we could have done with more spectators in the stadium, but there are pretty understandable reasons why that has been a challenge.
"They are not talking about [the crowds], and actually the athletes talking about externalities are probably not the ones who are going to be walking home with medals from here.
"We want a full stadium and that has to be the challenge, but we need to focus also on the absolute quality of what we are seeing here," Coe added, pointing out that athletes from 28 countries had won medals so far.
"I can't remember a World Championships actually that has delivered at this level for a long time."