It has been 20 years since the Socceroos last played in Tehran and while the city has not changed much, the experience has dramatically for long-time physiotherapist Les Gelis.

Gelis is the only current member of the national team set-up that was also part of the infamous 1998 World Cup qualifiers against Iran.

Few need any reminder of what happened in the second leg at the MCG - Australia were 2-0 up and looked like they were headed to France until serial pest Peter Hore ran onto the field, cut up Iran's goal net and halted all their momentum late in the second half.

The utter heartbreak of that night has perhaps overshadowed memories of the first leg, an impressive 1-1 draw in front of more than 128,000 fans at the Azadi Stadium.

The only female in the stands was the wife of former Soccer Australia boss David Hill.

Gelis recalls a picture of pure bedlam, and distinctly remembers supporters throwing hundreds of bread rolls onto the pitch because word had spread they had brought their own chef - something the Iranians interpreted as a swipe at their own food and culture.

"It was the first away trip I'd done," Gelis said.

"So coming back, it's nostalgic in a way but it's a totally different situation in terms of the football.

"Then it was so hostile, and this time it's so passive and comfortable."

Playing on neutral territory against Iraq - not Iran - on Thursday night (AEDT) is the chief reason why.

But because of Iranian New Year celebrations, millions of locals have left Tehran to attend family events elsewhere in the country - meaning no traffic, no air pollution, and generally no worries.

"The amount of groundwork that's gone into preparing to come, compared to then, is like night and day," Gelis said.

"The progress of the organisation - the sports science, the logistics - is huge. There's complete knowledge of what you're going into.

"Back then there were rats in the kitchen of the hotel we stayed in that night.

"There was no methodical planning, it was all about the finances."

No expenses are spared these days, with the Socceroos holed up in a glitzy five-star hotel in Tehran's north.

Despite the tense political situation in the country, there are no major security concerns around the team - but the wider landscape has impacted Iraq.

American-born midfielder Justin Meram ruled himself out of the match because of fears he may not have been able to return due to the United States' new travel ban.

AAP