Koreatimes - Korea coach Uli Stielike has been fond of saying lately that there are no easy games at this stage of qualification for the 2018 World Cup. This time, the German is definitely correct. The Taeguk Warriors are in Iran for another vital showdown.

Korea has never won in the country ― this is the fourth visit in the space of seven years ― but this would be a good time to start. Both teams have seven points from three games in the final round of qualification so far. Iran sits on top of Group A with a slightly better goal difference. Uzbekistan is third with six points, Syria has four, China one and Qatar has yet to pick up a point. The top two from the six-nation group automatically qualify for Russia 2018.

Stielike boarded the plane at Incheon International Airport on Friday a relieved man. At half-time in Thursday's game with Qatar at Suwon World Cup Stadium, the visitor was leading 2-1. Second half goals from Ji Dong-won and in-form Son Heung-min gave the host a very important win. It means that a draw at the cavernous Azadi Stadium, which saw 100,000 attend the same fixture between the two teams four years ago, would not be a bad result.

"It's not just the fact that Iran is a strong team," said captain Ki Sung-yeung, who scored the opening goal against Qatar and generally had a much-improved game compared to September's 3-2 win over China and 1-1 tie with Syria. "There is also the altitude which makes it difficult too."

Tehran lies around 1,200 meters above sea level. There are lots of stadiums around the world that are higher but with limited time to acclimatize, it makes things just that little bit trickier.

Iran, looking to qualify for a first back-to-back World Cup, is going well under experienced coach Carlos Queiroz. The wily former Real Madrid coach has led Team Melli to a win over Qatar, a tie in China and then a fine 1-0 victory in Uzbekistan on Thursday. He rested a few regular starters for that match. Iran should be a little fresher for the big game.

It remains to be seen as to what condition Son Heung-min is in. The Tottenham Hotspur man scored the winning goal against Qatar. It was his sixth goal in six games ― the 24 year-old is one of the most in-form players in the world right now. Yet he took a little punishment from the Qataris and left the stadium with his ankle wrapped in ice. A precaution, said the staff, but he has played a lot of football lately.

Hong Jeong-ho will miss the game as he was harshly sent off on Thursday. That will leave his fellow defenders to deal with the threat of another of Asia's big stars in Sardar Azmoun. The striker is hugely talented and has been linked with a move to Arsenal (the big London rivals of Son's Spurs). At the moment, the striker, 21, plays his club football in Russia but a move further west is not far away.

Names such as Masoud Shojaei and Andranik Teymourian will be familiar to Korean fans who have grown accustomed to facing Iran on a regular basis. The big absence is the legendary midfielder Javad Nekounam who scored the winning goal in Tehran when the two met in qualification for the 2014 World Cup. The Prince of Persia has retired.

The faces come and go but the size of the fixture remains. Korea and Iran have nothing but mutual respect for each other. Whichever teams wins on Tuesday will take a major step towards the World Cup. Tehran will be no place for the faint-hearted.