The visitors will hope the hosts will be disinterested in a tie that means nothing to them in technical terms, but Ecuador will not lie down with the opportunity to embarrass and humble Argentina. Colombia and Peru, who sit in fourth and fifth place on 26 and 25 points, respectively, play each other. One of the best stories from the 2014 World Cup is now in danger of a return appearance after just two points in their last three matches.
Renato Cesarini and Humberto Maschio were both dismissed, leaving Adolfo Pedernera to take charge of the 1970 World Cup qualifying campaign.
Third on 26 points, Chile need to buck a losing trend away to the already-qualified Brazil, where they have lost five qualifying matches out of five. Colombia, Peru, Paraguay, Argentina and Chile are all fighting for the remaining spots.
The situation in the South American qualifying looks like this - the top four teams after today's matches go through.
Argentina faces a monumental task in Ecuador not just because they're playing at altitude but because Sampaoli is battling his demons, because Argentina - and the world - need Messi in Russian Federation next summer for one last global showcase and because the scenes should they not qualify would be too disastrous for words. A draw would also be enough to get an automatic spot if Peru and Colombia draw, and Argentina fails to beat Ecuador.
In that doomsday scenario, it would depend on the result of the Peru-Colombia result as to whether Chile finished fifth or sixth.
"If they win and Brazil don't lose at home to Chile they qualify automatically".
Game on. A win would surely put Argentina through with 28 points, barring some unforeseen results elsewhere in South America. A win would grant them a playoff berth, and a win could even send them straight to Russian Federation.
Many people believe that winning a major trophy with Argentina will help Messi to be considered on Maradona's level, and Federation Internationale de Football Association president Gianni Infantino has echoed that sentiment.
Bono and U2 have agreed to delay their concert in Buenos Aires on Tuesday night until after Argentina's critical World Cup qualifier. If Peru win and Argentina don't, Peru get at least the playoff slot.
With a draw, Chile would be on 27 points, which could be passed by a Colombia-Peru victor and Argentina and tied by Paraguay, which would need to make up seven goals in goal differential.