Portugal, like France and Brazil, qualified for the knockout stages with a game to spare after defeating Uruguay 2-0 on Monday.
They only need a point against South Korea on Friday at 15:00 GMT to secure first place in the group.
Ghana will advance to the round of 16 if they defeat Uruguay. A draw will suffice as long as South Korea does not beat Portugal by more than two goals.
If Portugal loses and Ghana wins, the top spot will be determined by goal difference and goals scored.
South Korea has two options for advancing to the next round in Qatar, both of which require them to defeat Portugal.
If both Ghana and If Uruguay and South Korea draw, South Korea will need to defeat Portugal by two goals to advance.
If both Uruguay and South Korea win, the game will be decided by goal difference – and possibly goals scored – with the Asian team holding a one-goal advantage.
Uruguay’s most straightforward path to the last 16 is to defeat Ghana in their final match and hope that South Korea fails to defeat Portugal.
How are qualifications determined?
If teams are tied on points after three group games, goal difference determines progress. The complete tie-breaker criteria are as follows:
- accumulated points
- Difference in goals
- Scored goals
- Comparison results
- Fair play: the team with the fewest indiscipline points wins (a yellow card equals one point, a red card equals two yellows) a direct red card equals three points, a direct red card shown to a player who was already on a yellow equals four points, and a direct red card shown to a player who was already on a yellow equals five points)