Japan's men's national team faces a simple calculation in upcoming World Cup qualifiers against Iran and Qatar -- win to advance.

But with the absence of both its U.S.-based talents -- emerging Gonzaga University star and NBA draft hopeful Rui Hachimura and fringe Memphis Grizzlies swingman Yuta Watanabe -- it falls upon a platoon of local players to get the job done.

A place at the basketball World Cup is not the only thing at stake in the two games to be played over the next four days, however. Japan still must convince the sport's governing body that it warrants inclusion as host at the 2020 Tokyo Olympic Games.

If the team earns its fifth appearance at the competition formerly known as the World Championships, FIBA is unlikely to deny Japan a berth at the Tokyo Games when it makes the big decision in March.

Since making a horror start to qualifying, in which it dropped four straight games, including a crushing 70-69 loss to Taiwan, Japan has reeled off six straight victories.

But, at this point, past success means only so much.

In the first of the remaining qualifiers, Japan meets Asian heavyweights Iran on Thursday in Tehran.

"The team is in a good place," Japan's Argentinian coach Julio Lamas said in the lead-up to the game. "It is indeed going to be the most important game. We've come this far together, and as we are almost to the World Cup. We want to be well prepared and perform our best so there will be no regrets."

The last time the teams met, Hachimura and Watanabe keyed a big 70-56 win in Tokyo, but this time, the task is far more daunting.

Iran will likely see the return of formidable big man Hamed Haddadi, as well as the sharp-shooting Samad Nikkhah Bahrami. Both players have only featured in five of Iran's qualifiers but have made an impact in each of their appearances.

Haddadi, a former fringe NBA player, will match up with Japan's naturalized center Nik Fazekas.

Fazekas did not play in early qualifying, but has been stellar since replacing fellow U.S.-born player Ira Brown in the Japan squad. His touch from the post and ability to stretch defenses has proven a dangerous option for Lamas.

Against the lumbering 218-centimeter Haddadi, his stretch shooting will be key to opening up the lane for slashing teammates like Makoto Hiejima and Yudai Baba, but on the defensive end, he will need to match Haddadi blow for blow.

"Obviously (they are) very physical, they have a little bit of size. They can obviously shoot," said Fazekas at a recent training session in Tokyo.

"They like to slow it down and that is something we will have to counter."

(Nick Fazekas shoots during Japan's World Cup qualifier against Kazakhstan in December 2018)

Fazekas identified the battle on the boards as being key to Japan's success against Iran. If the Japanese big men can win their fair share of rebounds, it will ignite the team in transition, he believes.

"Transition baskets, easy baskets are going to be key," said the 33-year-old who has averaged 29.3 points and 12 rebounds in his four qualifying appearances.

"It seems to me they are a little bit more like they want to slow it down and want to play in the half court. If we can speed them up and get out in transition that will be good."

Lamas echoed his big man, identifying the need to keep Iran off the offensive boards -- limiting them to fewer than nine -- but had a different read on Iran's preferred pace of play.

"(We need) to avoid turnovers. No more than 10. The other team can attack with speed in transition. So we need to be careful."

The always efficient Hiejima has proven himself able to step up offensively when called upon.

He has notched double-figures in seven of the team's games while providing solid playmaking. He is averaging 52 percent from three, and 58 percent from the floor overall, adding near-flawless free-throw shooting to the mix.

In the previous game against Iran he took a back-seat to Japan's bigger names, but this time he knows he must take on more responsibility.

"I think I am, and the team is, expected to score, to attack the basket...I think that will be my job," he said.

Japan, having won six of 10 games and currently sitting third in its group, will be assured of a World Cup place with wins over both Iran and Qatar, but only one win may suffice depending on other results. If Iran proves too strong, Sunday's game in Doha will take on extra significance.

Happily for Lamas and company, Qatar has nothing to play for, having already been knocked out with a two-win, eight-loss record.

In the two teams' last meeting, in November in Toyama, Japan emerged an easy winner, 85-47.

Since then, Qatar was hammered by Australia and on Thursday they meet a Philippines team which, like Japan, is unlikely to go easy with a World Cup spot on the line.

If Japan loses both games and finds itself ranked fourth in the group, all is not lost. It can still qualify if it has a better record than the fourth-place finisher from Group E.

Currently, that team looks likely to be Jordan, which already has one fewer win than Japan and will play its remaining qualifiers against China and New Zealand, both formidable opponents who are unlikely to lay down.