Enner Valencia has shaken off a knee issue to represent Ecuador against Senegal in Group A.
The nation's record goalscorer has twice been forced off with the problem in previous matches, and had been a doubt for this contest.
However, the 33-year-old lines up on the left flank, while boss Gustavo Alfaro has seemingly opted to switch to a 4-3-3 formation.
Centre-back Jackson Porozo and midfielder Jhegson Mendez have dropped out of the side, with Carlos Gruezo and Alan Franco being introduced in their places.
Meanwhile, Senegal head coach Aliou Cisse has made three changes to the team which started the 3-1 triumph over Qatar on Friday.
Pathe Ciss, Pape Gueye and Iliman Ndiaye have all been brought into the side, with Nampalys Mendy, Krepin Diatta and Famara Diedhiou the trio to miss out.
Ecuador know that a point will be enough to earn a spot in the last 16 of the World Cup, while a Senegal win will ensure that they progress through to the knockout stages.
Ecuador: Galindez; Preciado, Torres, Hincapie, Estupinan; Franco, Gruezo, Caicedo; Plata, Estrada, Valencia
Senegal: Mendy; Sabaly, Koulibaly, Jakobs, Diallo; Ciss, P. Gueye; Ndiaye, I. Gueye, Sarr; Dia
