Ecuador captain Enner Valencia is hoping to recover from a knee injury in time to face Senegal
Ecuador will qualify for the next round if they avoid defeat against Senegal on Tuesday (15:00 GMT).
Alfaro's side are second in Group A after beating Qatar and drawing against group leaders the Netherlands.
"I'm convinced we've done everything we can, we've done our homework," head coach Alfaro said.
Should Ecuador progress, they will match their all-time best World Cup showing when they reached the last 16 at Germany 2006, where they were knocked out by England.
But they take on a Senegal side 26 places above them in the world rankings.
"We respect the pecking order, but we don't need to be fearful. We remain calm but that doesn't mean we are over-confident - we are not triumphalist," added Alfaro.
"We are not just thinking of getting a draw. We want to progress, we want to seal our passage, we want to play the best World Cup in Ecuadorean history."
Senegal, third in Group A with three points from their first two games, will be eliminated if they lose, and will likely need a victory to progress, unless hosts Qatar beat the Netherlands.
Coach Aliou Cisse has urged his players "not to overthink" the game and keep "cool heads".
"We are OK, we are dealing with pressure and stress. For me it is good stress," he added.
Ecuador are hopeful captain Enner Valencia, who has scored all three of their goals at this World Cup, will play at least some part in the game despite being forced off against the Netherlands with a knee injury.
Senegal have no new injury concerns.
-- Courtesy of BBC Sport