"Everything that we've done in the past will be useless tomorrow, it's a totally different game," coach Gustavo Alfaro said. "We just want to win in order to qualify."
The 44th-ranked South Americans beat World Cup hosts Qatar 2-0 before outplaying the Netherlands in a 1-1 draw to go joint top of Group A before Tuesday's final game of the round.
Should they avoid defeat, they will match their all-time best World Cup showing when they reached the last 16 in 2006.
"I'm convinced we've done everything we can, we've done our homework, hopefully tomorrow we will be strong and fortunate enough against Senegal, who are a great team, and hopefully we will go through, because we deserve it," Alfaro added.
Ecuador captain Enner Valencia has scored all three of their goals in Qatar, to add to the three he bagged at their last World Cup in 2014, but has been forced off the pitch with a sprained knee towards the end of each game.
"My knee's ok. I hope to make it ok to keep helping the team," he told reporters.
'BIG HEART'
Alfaro was not definitive about his striker's fitness, but said Valencia would of course be starting if he can.
"He has a big heart and he wants to be in every battle for our national team," he said. "He is an extraordinary player and I would always pick him. If not from the beginning, I hope he can be present at some point. But he will want to be there."
Alfaro said his team should expect their toughest game yet at the tournament against the African champions, who are ranked 26 places above them.
"We respect the picking 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," he said.
"We have our own way of playing, we are not just thinking of getting a draw. We have to come to the pitch trying to win the game ... We are creating our own pathway. We want to progress, we want to seal our passage, we want to play the best World Cup in Ecuadorean history."
Ecuador could still go through if they lose, but that would require a win by Qatar over the Netherlands, which looks improbable based on the hosts' form.
