International Friendly: Montenegro v Iran
Carlos Queiroz, who was in charge of Portugal at the 2010 World Cup, guided Iran to the top of their AFC qualifying group but a sterner test awaits them in Brazil.
Drawn in Group F alongside Nigeria, Argentina and Bosnia-Herzegovina, Queiroz's men face a huge challenge to build on their solitary World Cup finals win.
That came in 1998 against the United States in a match that was laden with off-field intrigue, given the strained political relationship between the two nations.
Controversy has shrouded the build-up to this year's tournament, too, with a falling-out occurring between the Iranian football association and the nation's top domestic clubs.
A warm-weather training camp in South Africa this month coincided with the AFC Champions League, in which several Iranian sides have been competing, leading some of them to refuse to release their players for international duty.
The episode has hampered their build-up significantly and disrupted the progress that Queiroz had been making.
Since reaching the tournament in South America, Iran have also qualified for the AFC Asian Cup having finished top of Group B without losing a game.
Midfielder Javad Nekounam has played a key role in his side's success, scoring four times in five Asian Cup qualifying matches and netting six goals in 14 games on the road to Brazil.
While the majority of the Iran squad are home-based, there are some more recognised names for Queiroz to call upon, most notably goalkeeper Daniel Davari of Eintracht Braunschweig and Fulham midfielder Ashkan Dejagah.
Montenegro fell short in their bid to qualify for the World Cup, with England claiming top spot in UEFA Group H and Ukraine taking the play-off place.
Dejan Damjanovic's first-minute penalty secured a 1-0 friendly win over Ghana in their last outing, while Friday's match against Slovakia ended in a 2-0 defeat.
Coach Branko Brnovic named four uncapped players in his squad for the meetings with Slovakia and Iran, with Danijel Petkovic, Sasa Balic, Darko Zoric and Miroje Jovanovic included.