But coach Jorge Sampaoli says his side fully deserve to be in Russia next year despite their underwhelming qualifying campaign.
Argentina, who reached the final three years ago in Brazil, lie in sixth place in the 10-team South American group, currently outside the qualifying places for Russia.
The top four qualify automatically and the fifth-placed side go into an intercontinental playoff against Oceania winners New Zealand.
“Argentina has shown the personality to demonstrate what it is, superior to the rest,” Sampaoli said in Ecuador on Monday.
“I hope we qualify because, looking beyond the numbers, Argentina deserves it.”
Argentina, who have won the World Cup twice, have taken just three points in their last four games. A win would guarantee Argentina at least fifth place but a draw might be enough to take them into the top four depending on results elsewhere.
Brazil have qualified already and Uruguay are almost certain to join them. Colombia, Peru, Paraguay, Argentina and Chile are all fighting for the remaining spots.
Sampaoli, who took over in June and has yet to record a competitive win, has not named his side for the match but Lionel Messi is sure to start.
“If we are up to Messi’s standards in tomorrow’s game then we’ll be alright,” Sampaoli said.
Argentina have beaten Ecuador only once in a World Cup qualifier in Quito, where the high altitude makes life difficult for visiting teams.