The double Olympic champion asked UK athletics performance director Neil Black to pick him for the shorter distance race as well as the longer races that made him famous in London last year.
But the scheduling of the distance races at the World Championships meant that it was impossible for him to try and win all three races.
"I said, ‘Neil, put me in the 1,500 metres. I want to run it as well as the 5,000 and 10,000,’" Farah told the Daily Telegraph.
"I was serious, but he said no because it didn’t fit in with the timetable."
Farah would have needed to run his 1500m semi-final on August 6 just an hour and 45 minutes before the 5000m final, which would have ended any chance of a medal.
But the British superstar - who is now set to race Usain Bolt over 600m in a charity race later this year - insists that 1500m is a realistic target for him in the future.
“I’m closer in the 1,500 than anything else,” he said, insisting that he could challenge the world record of three minutes 26 seconds. “I honestly think it’s closer.”
Farah is set to focus on long-distance racing next season, however: he will run the full London Marathon for the first time next April.
Yet he claims that it will not hamper his hopes of moving into shorter events.
“It’s a year when you can play around with things. Doing the marathon in April, there’s still quite a lot of time before the summer," he said.
"Sometimes when you don’t have a championship it’s nice to have four months to train for an event and see what you can do. I’m looking forward to that.”