After winning the 5,000 and 10,000 metres at London 2012, Mo Farah is already targeting another 'golden double' at the next Olympics.
His coach Alberto Salazar has confirmed that plans are being made despite the Rio Games being four years away.
Salazar said: "My guess is he will do a 10,000-marathon double, that would be a good shot. We will have a look at the schedule but if the 10 is first, he would go 10,000 and marathon."
Farah will try to recreate his Olympic double at next year's world championships in Moscow and would then consider making his marathon debut in London in April 2014.
Salazer added: "The way we look at it is pretty simple. He's the best long-distance runner on the track in the world right now....so why would you go from where you are the best in the world to something completely unknown?
"The only time it makes sense is that he could run the worlds in Moscow next summer and then do London in April, 2014. There is no worlds or Olympics in 2014, so he could run London and then still perhaps run a late track season in August.
"The exception will be if his track running is continuing to go so good that we feel, you know what, maybe he's tried a marathon, but if he's still on top in the 5,000, why would he go to marathon?"
