Iran take on Portugal in the final round of the 2018 World Cup group stage in Group B at the Mordovia Arena on Monday night.
Not many people would have expected Iran to have a chance of qualifying for the knockout stages of the competition at this stage, but this is what has turned out to be the case. They will need to beat Portugal in order to guarantee qualification.
Will Ronaldo add to his tally?
Portugal may not have performed as well as they did in their opening match against Spain when they took on Morocco last week, but they were still able to grind out a 1-0 victory to secure the three points. Cristiano Ronaldo picked up his fourth goal of the competition with a header after just four minutes, which turned out to be enough to win the game, despite a host of chances for Morocco going begging.
That goal was Ronaldo's 85th in international football, which is a European record. It would be no surprise to see him find the back of the net once again in this one to leapfrog Harry Kane who currently leads the race for the golden boot on five goals, having scored a hat-trick for England in their 6-1 win over Panama on Sunday afternoon.
There is a slight chance that Fernando Santos might opt to rest a couple of players considering that Portugal only need a point to guarantee their qualification for the knockout stages of the competition. However, due to Iran's performances so far, it is unlikely that he will take that sort of risk.
Portugal do come into this game with a couple of injury concerns. João Moutinho is a significant doubt having missed the last few days of training through illness. In addition to this, Raphaël Guerreiro has only just recovered from a minor leg injury so subsequently might not be risked in this match.
Can Iran cause a monumental shock?
Iran's performances so far at this tournament have come as a surprise to many people. They were expected by most people to finish bottom of this group, but they could yet end up winning it. They have the opportunity to qualify for the knockout stages of the World Cup for the first time in their history and they will be desperate to get the job done.
Carlos Queiroz's side were unlucky to lose 1-0 to Spain in their last match, ultimately being defeated by a deflected Diego Costa. They were able to frustrate the 2010 champions for large periods of the match, admittedly by using questionable tactics. Iran thought they had equalised in the latter stages of the game but had the goal ruled out by VAR, much to the despair of the players and the fans in the crowd.
If they are able to replicate this performance against Portugal, it would not be a surprise to see them pick up a result. They way they set themselves up makes them very difficult to play against which means that it may take something special from Ronaldo to break the deadlock. Queiroz does have some inside knowledge on Portugal having been their manager on two separate occasions, and it will be interesting to see whether he can use this to his side's advantage.
Iran could be without Olympiakos defender Ehsan Hajsafi for this match after he picked up a thigh injury against Spain, which could be a huge blow to their chances of putting in a similar defensive performance. Hajsafi's replacement is likely to be Milad Mohammadi.