Portugal only need to avoid losing to Iran this evening to clinch a spot in the World Cup's round of 16, as either a win or a draw can send them through. But the European champions are also looking to show more variety on offense, after Cristiano Ronaldo scored all of their goals against Spain and Morocco. Damion Jones has more.

Portugal will head into their final match in Group B looking to break a deadlock with Spain at the top of the table. The two neighbors from the Iberian Peninsula battled to a 3-3 draw in their World Cup opener, before the Portuguese defeated Morocco 1-0, and the Spaniards did the same to Iran last Wednesday. That leaves A Seleccao attempting to rev up their offense against the Iranians. Cristiano Ronaldo has been brilliant, accounting for all four goals from the Euro 2016 champions, but coach Fernando Santos wants to see a better overall team effort, when his men take to the pitch in Saransk.

FERNANDO SANTOS PORTUGAL COACH "Portugal is the team that has to win. This is a Portugal versus Iran match. This is not contest between the coaches of Iran and Portugal. Nor it is a game of Cristiano Ronaldo against anybody. This is a clash between a very strong team called Iran and another very strong team called Portugal. And I think that, in this match, we will be able to display our capabilities."

This is Iran's fifth trip to the global football showpiece, and a win in this contest would give the Persian Stars their first trip to the knockout phase. Coach Carlos Queiroz previously led Portugal from 2008 through 2010, and knows that his squad is facing a very tough task.

CARLOS QUEIROZ IRAN COACH "Since the first minute until the end, we know that we have a dream, we fight for a dream. We know we have nothing to lose, and against a great team, they fight for obligations and duties, because they have everything to lose, but we have nothing to lose. We have everything to win in this next game."

A defeat obviously eliminates the side from the Middle East, while a draw would leave them needing La Roja to lose to the Moroccans by multiple goals in Kaliningrad. One of the squads moving on from Group B gets to face tournament hosts Russia, while the other will take on Uruguay, in the Round of 16. DJ, CGTN.