Pogacar arrived in Tokyo with an iron grip on the peloton and will be the favourite to take the gold medal on a brutal 234km course that looks tailor-made for his vast skill set.

The 22-year-old was unbreakable in the Pyrenees and Alps on the way to a second successive Tour de France triumph, so tough climbs around Mount Fuji probably won't worry him.

While Saturday's race has a longer list of potential winners than a Grand Tour, Pogacar proved by winning the Liege-Bastonne-Liege classic this year that he can look after himself in a frenetic one-day classic.

"He rides carefree and loves the bike," UAE Team Emirates teammate Davide Formolo said during the Tour. "Everything seems easy to him. He wants to win and win, he's insatiable."

Even if Pogacar's gas tank is depleted from his exploits in France - the three-week tour finished just five days ago - Slovenia have an impressive "Plan B" in 2019 and 2020 Vuelta de Espana winner Primoz Roglic.

It's impressive firepower from a nation of two million people.

Roglic abandoned the Tour early after a crash after finishing runner-up to Pogacar last year.

If he has recovered physically, the recharged 31-year-old could be ready for a thrilling battle with his teammate.

The course starts at Musashinonomori Park and ends at the Fuji International Speedway and features five big ascents, including one on Mount Fuji itself.

But it is the final climb, the Mikuni Pass, after 200km of hard racing, that will likely decide the outcome.

If Pogacar's defences are not eroded by the time the race ascends that seven-kilometre brute, averaging 11 per cent, he will be hard to beat.

With less than a week between the Tour ending and the Olympic race, the big question is whether those who made it to Paris have recovered.

Top Australian contender Richie Porte and his teammates Lucas Hamilton and Luke Durbridge all rode the Tour, with Hamilton crashing out during stage 13.

"I've bumped into a lot of the Tour guys this week and they all look like corpses to be honest," New Zealand's George Bennett, another medal contender, told Reuters.

"I saw Wout (Van Aert) and he said he could hardly ride his bike for the first few days, but we will know more on Saturday."

Belgium's Van Aert, an all-rounder who could be deadly over the last 20 flat kilometres if not distanced on the final climb, is a serious rival to Pogacar.

He won three stages of the Tour and again showed he is a threat over any terrain.

As events in Rio proved five years ago, when Belgium's Greg van Avermaet took advantage of crashes to snatch gold in a thriller, the Olympic road race is wildly unpredictable and tactics often fly out the window.

If Pogacar's guard does slip, there will be plenty of riders ready to pounce including 2018 Tour de France champion Geraint Thomas, who heads a formidable British quartet of Tao Geoghegan Hart and Simon and Adam Yates.

Australian Associated Press