The striker, who has scored each of his country’s last six World Cup goals, was an injury doubt before the draw with the Netherlands and he ended that match on a stretcher.
Despite that, Ecuador are said to be confident that Valencia, 33, can start the final group game on Tuesday.
Sebas Mendez will sit out the game for La Tri due to suspension. Jose Cifuentes and Carlos Gruezo are competing to occupy his spot in the midfield.
Otherwise, Ecuador are likely to be unchanged in the 3-4-3 formation that has proven particularly difficult to break down in recent months.
Senegal could be unchanged while not suffering from any fresh injury concerns. Cheikhou Kouyate is set to miss out.
Bamba Dieng scored off the bench in the win over Qatar to stake his place while Tottenham midfielder Pape Matar Sarr is an option to reinforce the midfield.
Only a win will be enough for Senegal to progress to the last-16, presuming the Netherlands beat Qatar in the other Group A match. Ecuador will qualify with a draw.
Predicted Ecuador XI: Galindez; Porozo, Torres, Hincapie; Preciado, Gruezo, Caicedo, Estupinan; Plata, Estrada, Valencia.
Predicted Senegal XI: Mendy; Sabaly, Koulibaly, Diallo, Jakobs; Sarr, Mendy, Gueye, Diatta; Diedhiou, Dia.