The Tokyo Games have been pushed back a year because of COVID-19 and Coe says there are “no certainties” they will happen on the new date.
The two-time Olympic 1500m champion proposes other events could be organised to replace those cancelled.
“I really hope we are in a position to deliver the Tokyo Games,” he said.
Coe, speaking on BBC Radio 4’s Today Programme, continued: “We also may have to think slightly out of the box about how we might have to create other types of events if – I hope not – but if we have a very badly disrupted season generally.”
The president of the London 2012 organising committee added that should the Games have to take place without fans, it would still be worth doing but that the idea did not fill him “with unalloyed joy”.
In response to BBC Sport’s finding of 19 allegations of emotional abuse or neglect of British world-class programme athletes by coaches since 2017, Coe said those involved in sport cannot be “remotely complacent”.
He continued: “The most important thing that sports bodies need to do, whether they’re national or global, is to investigate reports of harassment and abuse and take it very seriously and with rigour. And it’s got to be a system that the athletes absolutely trust in.
“But what sports do need to be doing is talking more about where these vulnerabilities lie and actually speaking to themselves as well. We should have that conversation among sports generally.”
Earlier in August, the Russian Athletic Federation paid World Athletics a £4.8m fine relating to the country’s state-sponsored doping scandal to avoid removal by the governing body.
Coe said Rusaf must now present a restoration programme to World Athletics before the process of giving Russian athletes permission to compete as authorised neutral athletes could begin.
He added: “I’m hoping that we really can resume the reinstatement path, but it will only be achieved when I’m absolutely certain that we’re not putting in jeopardy the careers of clean athletes for those that have chosen to cheat.”