La Tri began their World Cup campaign by dominating hosts Qatar in a 2-0 victory and played out a 1-1 draw against the Netherlands in their following match, needing just a point here to qualify for the last 16. They can go through as group winners if they better the Oranje's result.
Manager Gustavo Alfaro has set up his side to attack with great fluidity while also maintaining the balance needed to defend in numbers.
For the Lions of Teranga, victory is required to ensure their progression at the tournament following a defeat to the Netherlands and a victory over Qatar while a draw would require help from the hosts to beat the Dutch.
Ecuador are seeking an appearance in the knockout phase of the World for the second time ever having previously qualified in 2006 while Senegal haven't gotten out of the group stage since their memorable quarterfinal run in 2002.
This is the first-ever meeting between Ecuador and Senegal with this contest kicking off at the same time as the Netherlands vs Qatar.
Star man Enner Valencia was stretchered off against the Netherlands with a hamstring injury and although he is status is not yet known, the expectation is that he will play.
Aliou Cisse has no new injury concerns ahead of this crucial match and his side found their scoring touch last time out against Qatar.
Ecuador: Domínguez; Estupiñán, Porozo, Torres, Hincapié, Preciado; Valencia, Caicedo, Gruezo, Plata; Estrada
Senegal: E. Mendy; Jakobs, Diallo, Koulibaly, Sabaly; Gueye, N. Mendy; Diatta, Sarr; Diédhiou, Dia
Pervis Estupinan (Ecuador)
He has the ability to get forward in great effect, is strong at the back, can recover well and he is particularly dangerous on set pieces with pinpoint crosses.
Idrissa Gueye (Senegal)
The 32-year old is the heartbeat of the Lions of Teranga. Among his many skills is the ability to speed the pace of the game up or slow it down while he is also proficient at creating overlaps and delivering the final pass.
Excelling at intercepting and winning the ball, Gueye reads the game brilliantly, a perfect fit for Senegal's style of play and his ability to thrive under pressure, as shown when his country won the African Cup of Nations, makes him perfectly suited for this match.
Where is the match being played?
The Khalifa International Stadium will host this match, the fourth of eight to be played at the venue with two more group stage contests, a Round of 16 and the third-place playoff also scheduled at the 45,857-seat facility.
What time is the match?
How can I watch the match?
In the UK, the BBC will have all of the action while FOX Sports 1 and Telemundo cover the match in the United States.
In Ecuador, Teleamazonas will carry the match while RTS has the coverage in Senegal.